{"openapi":"3.1.0","info":{"title":"Bizday","version":"0.3.2","summary":"US federal office and Reserve Bank business days.","description":"Verified US business-day calendars. Dates are civil dates (YYYY-MM-DD), never timestamps. Omit calendar and the calendar is us-federal-opm. us-fed-banking is the Federal Reserve Banks and Branches schedule: a Saturday holiday does not close the preceding Friday. The Board of Governors closes that Friday; this calendar does not. A Sunday holiday closes the following Monday on both calendars. add matches Excel WORKDAY: the start date is day 0. diff matches Excel NETWORKDAYS: both ends count when they are business days. roll stays on a business day and otherwise moves to the nearest one in the requested direction. roll is not Excel WORKDAY, and it does not decide whether a filing is timely. Inauguration Day is reported on the office calendar and is not a nationwide closing. It is not a Reserve Bank holiday. Coverage is 2021-01-01 through 2100-12-31. Years after 2030 use the same rules and are not a copy of a later official table. Preview traffic is 60 requests per minute per IP on the calculation routes and on MCP tool calls. GET /v1, GET /v1/health, GET /openapi.json, GET /llms.txt, GET /.well-known/mcp.json, and GET /.well-known/mcp/server-card.json are not counted. MCP initialize, ping, server/discover, and tools/list are not counted. There is no API key. Not legal, payroll, or financial advice. Human docs are on /. Agent instructions are at /llms.txt and point here. POST /mcp is streamable HTTP MCP for is_business_day, add_business_days, count_business_days, roll_date, list_holidays, and list_calendars. The manifest is GET /.well-known/mcp.json. The server card is GET /.well-known/mcp/server-card.json. This document's server URL is https://isitabizday.com."},"servers":[{"url":"https://isitabizday.com","description":"Public HTTPS origin. Paths in this document start with /."}],"paths":{"/v1":{"get":{"operationId":"describe_service","summary":"Service index","description":"Version, coverage, endpoint list, and the paths of this OpenAPI document, /llms.txt, the MCP endpoint, and the MCP server card. Not rate limited.","parameters":[],"responses":{"200":{"description":"Service index.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/ServiceIndex"}}}},"400":{"$ref":"#/components/responses/BadRequest"}}}},"/v1/health":{"get":{"operationId":"get_health","summary":"Liveness","description":"Process is up. Not rate limited.","parameters":[],"responses":{"200":{"description":"Liveness.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Health"},"example":{"ok":true,"service":"bizday","version":"0.3.2","calendar":"us-federal-opm"}}}},"400":{"$ref":"#/components/responses/BadRequest"}}}},"/v1/calendars":{"get":{"operationId":"list_calendars","summary":"List verified calendars","description":"Id, name, source URL, Saturday and Sunday rules, coverage, last verified, and changelog for each shipped calendar.","parameters":[],"responses":{"200":{"description":"Calendar registry.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/CalendarList"},"example":{"default":"us-federal-opm","calendars":[{"id":"us-federal-opm","name":"US federal offices (OPM Monday–Friday)","default":true,"source_url":"https://www.opm.gov/policy-data-oversight/pay-leave/federal-holidays/","sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"coverage":{"from":"2021-01-01","to":"2100-12-31"},"last_verified":"2026-10-17","saturday_rule":"Observed the preceding Friday (5 U.S.C. § 6103(b)(1)).","sunday_rule":"Observed the following Monday (Executive Order 11582 § 3(a)).","changelog":[{"date":"2026-10-17","change":"Initial calendar from 5 U.S.C. § 6103 and the OPM Monday–Friday tables for 2021–2030."}],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."},{"id":"us-fed-banking","name":"Federal Reserve Banks and Branches","default":false,"source_url":"https://www.federalreserve.gov/aboutthefed/k8.htm","sources":["Board of Governors, K.8 Holidays Observed by the Federal Reserve System, https://www.federalreserve.gov/aboutthefed/k8.htm (2026–2030 table, last update July 8, 2026, checked 2026-10-17). Saturday: Banks open the preceding Friday, Board of Governors closed. Sunday: Banks and the Board closed the following Monday.","K.8 as of 2022-06-30, captured 2022-07-01: 2022–2026 table. Sunday closings include June 20, 2022, December 26, 2022, and January 2, 2023. https://web.archive.org/web/20220701092245/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2022-12-30, captured 2023-01-19: 2023–2027 table, including Juneteenth. https://web.archive.org/web/20230119211335/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2024-01-05, captured 2024-06-14: 2024–2028 table. The New Year’s Day 2028 footnote is December 31, 2027. https://web.archive.org/web/20240614134448/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2021-01-04, harvested 2021-01-16: 2021–2025 table, published before Juneteenth. https://webharvest.gov/congress116th/20210116025255/https://www.federalreserve.gov/aboutthefed/k8.htm","Federal Reserve Board press release, June 17, 2021: payment services stayed open on Friday, June 18, 2021, because Juneteenth fell on Saturday. https://www.federalreserve.gov/newsevents/pressreleases/other20210617b.htm"],"coverage":{"from":"2021-01-01","to":"2100-12-31"},"last_verified":"2026-10-17","saturday_rule":"Banks stay open the preceding Friday. The Board of Governors is closed that Friday. K.8.","sunday_rule":"Banks and the Board of Governors are closed the following Monday. K.8.","changelog":[{"date":"2026-10-17","change":"Transcribed Reserve Bank closings for 2021–2030 from K.8. Saturday holidays do not close Friday."}],"disclaimer":"Weekday closings are the Federal Reserve Banks and Branches schedule from K.8. A Saturday holiday does not close the preceding Friday: the Banks stay open, and the Board of Governors in Washington is closed. A Sunday holiday closes the following Monday. This is not the OPM federal-employee schedule, not Inauguration Day, and not ACH or Fedwire operating hours. The October 9, 2025 announcement about later Fedwire Funds and National Settlement Service hours is not applied. Not legal, payroll, or financial advice."}]},"examples":{"registry":{"summary":"Both shipped calendars","value":{"default":"us-federal-opm","calendars":[{"id":"us-federal-opm","name":"US federal offices (OPM Monday–Friday)","default":true,"source_url":"https://www.opm.gov/policy-data-oversight/pay-leave/federal-holidays/","sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"coverage":{"from":"2021-01-01","to":"2100-12-31"},"last_verified":"2026-10-17","saturday_rule":"Observed the preceding Friday (5 U.S.C. § 6103(b)(1)).","sunday_rule":"Observed the following Monday (Executive Order 11582 § 3(a)).","changelog":[{"date":"2026-10-17","change":"Initial calendar from 5 U.S.C. § 6103 and the OPM Monday–Friday tables for 2021–2030."}],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."},{"id":"us-fed-banking","name":"Federal Reserve Banks and Branches","default":false,"source_url":"https://www.federalreserve.gov/aboutthefed/k8.htm","sources":["Board of Governors, K.8 Holidays Observed by the Federal Reserve System, https://www.federalreserve.gov/aboutthefed/k8.htm (2026–2030 table, last update July 8, 2026, checked 2026-10-17). Saturday: Banks open the preceding Friday, Board of Governors closed. Sunday: Banks and the Board closed the following Monday.","K.8 as of 2022-06-30, captured 2022-07-01: 2022–2026 table. Sunday closings include June 20, 2022, December 26, 2022, and January 2, 2023. https://web.archive.org/web/20220701092245/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2022-12-30, captured 2023-01-19: 2023–2027 table, including Juneteenth. https://web.archive.org/web/20230119211335/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2024-01-05, captured 2024-06-14: 2024–2028 table. The New Year’s Day 2028 footnote is December 31, 2027. https://web.archive.org/web/20240614134448/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2021-01-04, harvested 2021-01-16: 2021–2025 table, published before Juneteenth. https://webharvest.gov/congress116th/20210116025255/https://www.federalreserve.gov/aboutthefed/k8.htm","Federal Reserve Board press release, June 17, 2021: payment services stayed open on Friday, June 18, 2021, because Juneteenth fell on Saturday. https://www.federalreserve.gov/newsevents/pressreleases/other20210617b.htm"],"coverage":{"from":"2021-01-01","to":"2100-12-31"},"last_verified":"2026-10-17","saturday_rule":"Banks stay open the preceding Friday. The Board of Governors is closed that Friday. K.8.","sunday_rule":"Banks and the Board of Governors are closed the following Monday. K.8.","changelog":[{"date":"2026-10-17","change":"Transcribed Reserve Bank closings for 2021–2030 from K.8. Saturday holidays do not close Friday."}],"disclaimer":"Weekday closings are the Federal Reserve Banks and Branches schedule from K.8. A Saturday holiday does not close the preceding Friday: the Banks stay open, and the Board of Governors in Washington is closed. A Sunday holiday closes the following Monday. This is not the OPM federal-employee schedule, not Inauguration Day, and not ACH or Fedwire operating hours. The October 9, 2025 announcement about later Fedwire Funds and National Settlement Service hours is not applied. Not legal, payroll, or financial advice."}]}}}}},"headers":{"X-RateLimit-Limit":{"description":"Requests allowed in the current one-minute window for this IP.","schema":{"type":"integer"}},"X-RateLimit-Remaining":{"description":"Requests remaining in the current window.","schema":{"type":"integer"}},"X-RateLimit-Reset":{"description":"Unix time when the window resets.","schema":{"type":"integer"}}}},"400":{"$ref":"#/components/responses/BadRequest"},"429":{"$ref":"#/components/responses/RateLimited"}}}},"/v1/holidays":{"get":{"operationId":"list_holidays","summary":"Holidays in one legal year","description":"The eleven nationwide legal public holidays. On us-federal-opm, observed is the weekday off. On us-fed-banking, observed is null when the legal date is a Saturday, because Friday stays open.","parameters":[{"name":"year","in":"query","required":true,"description":"Legal year, 2021 through 2100.","schema":{"type":"integer","minimum":2021,"maximum":2100}},{"name":"calendar","in":"query","required":false,"description":"us-federal-opm: US federal offices (OPM Monday–Friday). This is the default when calendar is omitted. Saturday: Observed the preceding Friday (5 U.S.C. § 6103(b)(1)). Sunday: Observed the following Monday (Executive Order 11582 § 3(a)). Source: https://www.opm.gov/policy-data-oversight/pay-leave/federal-holidays/. us-fed-banking: Federal Reserve Banks and Branches. Saturday: Banks stay open the preceding Friday. The Board of Governors is closed that Friday. K.8. Sunday: Banks and the Board of Governors are closed the following Monday. K.8. Source: https://www.federalreserve.gov/aboutthefed/k8.htm. Unknown ids return 400 invalid_calendar.","schema":{"$ref":"#/components/schemas/CalendarId"}}],"responses":{"200":{"description":"Eleven holidays for that legal year.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/HolidayYear"},"example":{"calendar":"us-federal-opm","year":2026,"count":11,"holidays":[{"name":"New Year's Day","actual":"2026-01-01","observed":"2026-01-01","actual_weekday":"Thursday","observed_weekday":"Thursday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Birthday of Martin Luther King, Jr.","actual":"2026-01-19","observed":"2026-01-19","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Washington's Birthday","actual":"2026-02-16","observed":"2026-02-16","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Memorial Day","actual":"2026-05-25","observed":"2026-05-25","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Juneteenth National Independence Day","actual":"2026-06-19","observed":"2026-06-19","actual_weekday":"Friday","observed_weekday":"Friday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Independence Day","actual":"2026-07-04","observed":"2026-07-03","actual_weekday":"Saturday","observed_weekday":"Friday","observed_shifted":true,"closes_weekday":true,"shift_rule":"5usc6103b1-saturday-to-friday"},{"name":"Labor Day","actual":"2026-09-07","observed":"2026-09-07","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Columbus Day","actual":"2026-10-12","observed":"2026-10-12","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Veterans Day","actual":"2026-11-11","observed":"2026-11-11","actual_weekday":"Wednesday","observed_weekday":"Wednesday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Thanksgiving Day","actual":"2026-11-26","observed":"2026-11-26","actual_weekday":"Thursday","observed_weekday":"Thursday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Christmas Day","actual":"2026-12-25","observed":"2026-12-25","actual_weekday":"Friday","observed_weekday":"Friday","observed_shifted":false,"closes_weekday":true,"shift_rule":null}],"excluded":["Inauguration Day (Washington, DC area only, 5 U.S.C. § 6103(c))","state and local holidays","Federal Reserve Bank holidays where they differ (see us-fed-banking)","stock-exchange holidays"],"sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."},"examples":{"offices_2026":{"summary":"OPM observed dates for 2026, including Friday July 3","value":{"calendar":"us-federal-opm","year":2026,"count":11,"holidays":[{"name":"New Year's Day","actual":"2026-01-01","observed":"2026-01-01","actual_weekday":"Thursday","observed_weekday":"Thursday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Birthday of Martin Luther King, Jr.","actual":"2026-01-19","observed":"2026-01-19","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Washington's Birthday","actual":"2026-02-16","observed":"2026-02-16","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Memorial Day","actual":"2026-05-25","observed":"2026-05-25","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Juneteenth National Independence Day","actual":"2026-06-19","observed":"2026-06-19","actual_weekday":"Friday","observed_weekday":"Friday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Independence Day","actual":"2026-07-04","observed":"2026-07-03","actual_weekday":"Saturday","observed_weekday":"Friday","observed_shifted":true,"closes_weekday":true,"shift_rule":"5usc6103b1-saturday-to-friday"},{"name":"Labor Day","actual":"2026-09-07","observed":"2026-09-07","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Columbus Day","actual":"2026-10-12","observed":"2026-10-12","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Veterans Day","actual":"2026-11-11","observed":"2026-11-11","actual_weekday":"Wednesday","observed_weekday":"Wednesday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Thanksgiving Day","actual":"2026-11-26","observed":"2026-11-26","actual_weekday":"Thursday","observed_weekday":"Thursday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Christmas Day","actual":"2026-12-25","observed":"2026-12-25","actual_weekday":"Friday","observed_weekday":"Friday","observed_shifted":false,"closes_weekday":true,"shift_rule":null}],"excluded":["Inauguration Day (Washington, DC area only, 5 U.S.C. § 6103(c))","state and local holidays","Federal Reserve Bank holidays where they differ (see us-fed-banking)","stock-exchange holidays"],"sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."}},"banks_2026":{"summary":"Reserve Banks: July 4 2026 is Saturday, so observed is null","value":{"calendar":"us-fed-banking","year":2026,"count":11,"holidays":[{"name":"New Year's Day","actual":"2026-01-01","observed":"2026-01-01","actual_weekday":"Thursday","observed_weekday":"Thursday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Birthday of Martin Luther King, Jr.","actual":"2026-01-19","observed":"2026-01-19","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Washington's Birthday","actual":"2026-02-16","observed":"2026-02-16","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Memorial Day","actual":"2026-05-25","observed":"2026-05-25","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Juneteenth National Independence Day","actual":"2026-06-19","observed":"2026-06-19","actual_weekday":"Friday","observed_weekday":"Friday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Independence Day","actual":"2026-07-04","observed":null,"actual_weekday":"Saturday","observed_weekday":null,"observed_shifted":false,"closes_weekday":false,"shift_rule":"k8-saturday-banks-open"},{"name":"Labor Day","actual":"2026-09-07","observed":"2026-09-07","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Columbus Day","actual":"2026-10-12","observed":"2026-10-12","actual_weekday":"Monday","observed_weekday":"Monday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Veterans Day","actual":"2026-11-11","observed":"2026-11-11","actual_weekday":"Wednesday","observed_weekday":"Wednesday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Thanksgiving Day","actual":"2026-11-26","observed":"2026-11-26","actual_weekday":"Thursday","observed_weekday":"Thursday","observed_shifted":false,"closes_weekday":true,"shift_rule":null},{"name":"Christmas Day","actual":"2026-12-25","observed":"2026-12-25","actual_weekday":"Friday","observed_weekday":"Friday","observed_shifted":false,"closes_weekday":true,"shift_rule":null}],"excluded":["Board of Governors Friday closure when the legal holiday is a Saturday","Inauguration Day (Board of Governors in Washington; Reserve Banks stay open unless the date is also a Bank holiday)","ACH file-cutoff times and Fedwire operating hours","OPM federal-employee in-lieu-of days (see us-federal-opm)","stock-exchange holidays"],"sources":["Board of Governors, K.8 Holidays Observed by the Federal Reserve System, https://www.federalreserve.gov/aboutthefed/k8.htm (2026–2030 table, last update July 8, 2026, checked 2026-10-17). Saturday: Banks open the preceding Friday, Board of Governors closed. Sunday: Banks and the Board closed the following Monday.","K.8 as of 2022-06-30, captured 2022-07-01: 2022–2026 table. Sunday closings include June 20, 2022, December 26, 2022, and January 2, 2023. https://web.archive.org/web/20220701092245/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2022-12-30, captured 2023-01-19: 2023–2027 table, including Juneteenth. https://web.archive.org/web/20230119211335/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2024-01-05, captured 2024-06-14: 2024–2028 table. The New Year’s Day 2028 footnote is December 31, 2027. https://web.archive.org/web/20240614134448/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2021-01-04, harvested 2021-01-16: 2021–2025 table, published before Juneteenth. https://webharvest.gov/congress116th/20210116025255/https://www.federalreserve.gov/aboutthefed/k8.htm","Federal Reserve Board press release, June 17, 2021: payment services stayed open on Friday, June 18, 2021, because Juneteenth fell on Saturday. https://www.federalreserve.gov/newsevents/pressreleases/other20210617b.htm"],"disclaimer":"Weekday closings are the Federal Reserve Banks and Branches schedule from K.8. A Saturday holiday does not close the preceding Friday: the Banks stay open, and the Board of Governors in Washington is closed. A Sunday holiday closes the following Monday. This is not the OPM federal-employee schedule, not Inauguration Day, and not ACH or Fedwire operating hours. The October 9, 2025 announcement about later Fedwire Funds and National Settlement Service hours is not applied. Not legal, payroll, or financial advice."}}}}},"headers":{"X-RateLimit-Limit":{"description":"Requests allowed in the current one-minute window for this IP.","schema":{"type":"integer"}},"X-RateLimit-Remaining":{"description":"Requests remaining in the current window.","schema":{"type":"integer"}},"X-RateLimit-Reset":{"description":"Unix time when the window resets.","schema":{"type":"integer"}}}},"400":{"$ref":"#/components/responses/BadRequest"},"429":{"$ref":"#/components/responses/RateLimited"}}}},"/v1/business-days/check":{"get":{"operationId":"is_business_day","summary":"Is this date a business day?","description":"Weekday, weekend, holiday rows that touch the date, the previous and next business days, and dc_inauguration on the office calendar. A date is a business day when it is Monday–Friday and no holiday row closes it.","parameters":[{"name":"date","in":"query","required":true,"description":"The civil date to classify.","schema":{"type":"string","pattern":"^\\d{4}-\\d{2}-\\d{2}$","description":"Civil date, YYYY-MM-DD. Not a timestamp."}},{"name":"calendar","in":"query","required":false,"description":"us-federal-opm: US federal offices (OPM Monday–Friday). This is the default when calendar is omitted. Saturday: Observed the preceding Friday (5 U.S.C. § 6103(b)(1)). Sunday: Observed the following Monday (Executive Order 11582 § 3(a)). Source: https://www.opm.gov/policy-data-oversight/pay-leave/federal-holidays/. us-fed-banking: Federal Reserve Banks and Branches. Saturday: Banks stay open the preceding Friday. The Board of Governors is closed that Friday. K.8. Sunday: Banks and the Board of Governors are closed the following Monday. K.8. Source: https://www.federalreserve.gov/aboutthefed/k8.htm. Unknown ids return 400 invalid_calendar.","schema":{"$ref":"#/components/schemas/CalendarId"}}],"responses":{"200":{"description":"Classification of one civil date.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/CheckResult"},"example":{"calendar":"us-federal-opm","date":"2026-07-03","weekday":"Friday","weekend":false,"business_day":false,"holidays":[{"name":"Independence Day","actual":"2026-07-04","observed":"2026-07-03","actual_weekday":"Saturday","observed_weekday":"Friday","observed_shifted":true,"closes_weekday":true,"shift_rule":"5usc6103b1-saturday-to-friday","on_this_date":"observed","closes_the_day":true}],"dc_inauguration":null,"following_business_day":"2026-07-06","preceding_business_day":"2026-07-02","sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."},"examples":{"offices_closed":{"summary":"Friday 2026-07-03 is Independence Day observed for federal offices","value":{"calendar":"us-federal-opm","date":"2026-07-03","weekday":"Friday","weekend":false,"business_day":false,"holidays":[{"name":"Independence Day","actual":"2026-07-04","observed":"2026-07-03","actual_weekday":"Saturday","observed_weekday":"Friday","observed_shifted":true,"closes_weekday":true,"shift_rule":"5usc6103b1-saturday-to-friday","on_this_date":"observed","closes_the_day":true}],"dc_inauguration":null,"following_business_day":"2026-07-06","preceding_business_day":"2026-07-02","sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."}},"banks_open":{"summary":"The same Friday is a Reserve Bank business day","value":{"calendar":"us-fed-banking","date":"2026-07-03","weekday":"Friday","weekend":false,"business_day":true,"holidays":[],"dc_inauguration":null,"following_business_day":"2026-07-06","preceding_business_day":"2026-07-02","sources":["Board of Governors, K.8 Holidays Observed by the Federal Reserve System, https://www.federalreserve.gov/aboutthefed/k8.htm (2026–2030 table, last update July 8, 2026, checked 2026-10-17). Saturday: Banks open the preceding Friday, Board of Governors closed. Sunday: Banks and the Board closed the following Monday.","K.8 as of 2022-06-30, captured 2022-07-01: 2022–2026 table. Sunday closings include June 20, 2022, December 26, 2022, and January 2, 2023. https://web.archive.org/web/20220701092245/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2022-12-30, captured 2023-01-19: 2023–2027 table, including Juneteenth. https://web.archive.org/web/20230119211335/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2024-01-05, captured 2024-06-14: 2024–2028 table. The New Year’s Day 2028 footnote is December 31, 2027. https://web.archive.org/web/20240614134448/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2021-01-04, harvested 2021-01-16: 2021–2025 table, published before Juneteenth. https://webharvest.gov/congress116th/20210116025255/https://www.federalreserve.gov/aboutthefed/k8.htm","Federal Reserve Board press release, June 17, 2021: payment services stayed open on Friday, June 18, 2021, because Juneteenth fell on Saturday. https://www.federalreserve.gov/newsevents/pressreleases/other20210617b.htm"],"disclaimer":"Weekday closings are the Federal Reserve Banks and Branches schedule from K.8. A Saturday holiday does not close the preceding Friday: the Banks stay open, and the Board of Governors in Washington is closed. A Sunday holiday closes the following Monday. This is not the OPM federal-employee schedule, not Inauguration Day, and not ACH or Fedwire operating hours. The October 9, 2025 announcement about later Fedwire Funds and National Settlement Service hours is not applied. Not legal, payroll, or financial advice."}}}}},"headers":{"X-RateLimit-Limit":{"description":"Requests allowed in the current one-minute window for this IP.","schema":{"type":"integer"}},"X-RateLimit-Remaining":{"description":"Requests remaining in the current window.","schema":{"type":"integer"}},"X-RateLimit-Reset":{"description":"Unix time when the window resets.","schema":{"type":"integer"}}}},"400":{"$ref":"#/components/responses/BadRequest"},"429":{"$ref":"#/components/responses/RateLimited"}}}},"/v1/business-days/add":{"get":{"operationId":"add_business_days","summary":"Add business days","description":"Excel WORKDAY shape. The start date is day 0, so days=1 is the next business day and days=0 returns the start date even when it is closed. days may be negative.","parameters":[{"name":"start","in":"query","required":true,"description":"Day 0. Not counted.","schema":{"type":"string","pattern":"^\\d{4}-\\d{2}-\\d{2}$","description":"Civil date, YYYY-MM-DD. Not a timestamp."}},{"name":"days","in":"query","required":true,"description":"Integer from -3660 to 3660. Zero returns start unchanged.","schema":{"type":"integer","minimum":-3660,"maximum":3660}},{"name":"calendar","in":"query","required":false,"description":"us-federal-opm: US federal offices (OPM Monday–Friday). This is the default when calendar is omitted. Saturday: Observed the preceding Friday (5 U.S.C. § 6103(b)(1)). Sunday: Observed the following Monday (Executive Order 11582 § 3(a)). Source: https://www.opm.gov/policy-data-oversight/pay-leave/federal-holidays/. us-fed-banking: Federal Reserve Banks and Branches. Saturday: Banks stay open the preceding Friday. The Board of Governors is closed that Friday. K.8. Sunday: Banks and the Board of Governors are closed the following Monday. K.8. Source: https://www.federalreserve.gov/aboutthefed/k8.htm. Unknown ids return 400 invalid_calendar.","schema":{"$ref":"#/components/schemas/CalendarId"}}],"responses":{"200":{"description":"The resulting civil date.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/AddResult"},"example":{"calendar":"us-federal-opm","start":"2026-07-02","days":1,"date":"2026-07-06","business_day":true,"convention":"The start date is day 0 and is not counted. Saturdays, Sundays, and observed US federal holidays are skipped. Same convention as Excel WORKDAY with this holiday list.","sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."},"examples":{"offices":{"summary":"One office business day after 2026-07-02 is 2026-07-06","value":{"calendar":"us-federal-opm","start":"2026-07-02","days":1,"date":"2026-07-06","business_day":true,"convention":"The start date is day 0 and is not counted. Saturdays, Sundays, and observed US federal holidays are skipped. Same convention as Excel WORKDAY with this holiday list.","sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."}},"banks":{"summary":"One Reserve Bank business day after 2026-07-02 is 2026-07-03","value":{"calendar":"us-fed-banking","start":"2026-07-02","days":1,"date":"2026-07-03","business_day":true,"convention":"The start date is day 0 and is not counted. Saturdays, Sundays, and Reserve Bank weekday closings are skipped. A Saturday holiday does not close the preceding Friday. Same shape as Excel WORKDAY with this holiday list.","sources":["Board of Governors, K.8 Holidays Observed by the Federal Reserve System, https://www.federalreserve.gov/aboutthefed/k8.htm (2026–2030 table, last update July 8, 2026, checked 2026-10-17). Saturday: Banks open the preceding Friday, Board of Governors closed. Sunday: Banks and the Board closed the following Monday.","K.8 as of 2022-06-30, captured 2022-07-01: 2022–2026 table. Sunday closings include June 20, 2022, December 26, 2022, and January 2, 2023. https://web.archive.org/web/20220701092245/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2022-12-30, captured 2023-01-19: 2023–2027 table, including Juneteenth. https://web.archive.org/web/20230119211335/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2024-01-05, captured 2024-06-14: 2024–2028 table. The New Year’s Day 2028 footnote is December 31, 2027. https://web.archive.org/web/20240614134448/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2021-01-04, harvested 2021-01-16: 2021–2025 table, published before Juneteenth. https://webharvest.gov/congress116th/20210116025255/https://www.federalreserve.gov/aboutthefed/k8.htm","Federal Reserve Board press release, June 17, 2021: payment services stayed open on Friday, June 18, 2021, because Juneteenth fell on Saturday. https://www.federalreserve.gov/newsevents/pressreleases/other20210617b.htm"],"disclaimer":"Weekday closings are the Federal Reserve Banks and Branches schedule from K.8. A Saturday holiday does not close the preceding Friday: the Banks stay open, and the Board of Governors in Washington is closed. A Sunday holiday closes the following Monday. This is not the OPM federal-employee schedule, not Inauguration Day, and not ACH or Fedwire operating hours. The October 9, 2025 announcement about later Fedwire Funds and National Settlement Service hours is not applied. Not legal, payroll, or financial advice."}}}}},"headers":{"X-RateLimit-Limit":{"description":"Requests allowed in the current one-minute window for this IP.","schema":{"type":"integer"}},"X-RateLimit-Remaining":{"description":"Requests remaining in the current window.","schema":{"type":"integer"}},"X-RateLimit-Reset":{"description":"Unix time when the window resets.","schema":{"type":"integer"}}}},"400":{"$ref":"#/components/responses/BadRequest"},"429":{"$ref":"#/components/responses/RateLimited"}}}},"/v1/business-days/diff":{"get":{"operationId":"count_business_days","summary":"Count business days in an inclusive span","description":"Excel NETWORKDAYS shape. Both endpoints count when they are business days. The sign is negative when end is before start. The inclusive span must be 3660 days or less.","parameters":[{"name":"start","in":"query","required":true,"description":"First civil date of the span.","schema":{"type":"string","pattern":"^\\d{4}-\\d{2}-\\d{2}$","description":"Civil date, YYYY-MM-DD. Not a timestamp."}},{"name":"end","in":"query","required":true,"description":"Last civil date of the span.","schema":{"type":"string","pattern":"^\\d{4}-\\d{2}-\\d{2}$","description":"Civil date, YYYY-MM-DD. Not a timestamp."}},{"name":"calendar","in":"query","required":false,"description":"us-federal-opm: US federal offices (OPM Monday–Friday). This is the default when calendar is omitted. Saturday: Observed the preceding Friday (5 U.S.C. § 6103(b)(1)). Sunday: Observed the following Monday (Executive Order 11582 § 3(a)). Source: https://www.opm.gov/policy-data-oversight/pay-leave/federal-holidays/. us-fed-banking: Federal Reserve Banks and Branches. Saturday: Banks stay open the preceding Friday. The Board of Governors is closed that Friday. K.8. Sunday: Banks and the Board of Governors are closed the following Monday. K.8. Source: https://www.federalreserve.gov/aboutthefed/k8.htm. Unknown ids return 400 invalid_calendar.","schema":{"$ref":"#/components/schemas/CalendarId"}}],"responses":{"200":{"description":"Signed inclusive business-day count.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/DiffResult"},"example":{"calendar":"us-federal-opm","start":"2026-11-25","end":"2026-11-27","business_days":2,"convention":"Both endpoints count when they are business days, matching Excel NETWORKDAYS. The sign is negative when end is before start.","sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."},"examples":{"thanksgiving_week_2026":{"summary":"2026-11-25 through 2026-11-27 is 2 office business days","value":{"calendar":"us-federal-opm","start":"2026-11-25","end":"2026-11-27","business_days":2,"convention":"Both endpoints count when they are business days, matching Excel NETWORKDAYS. The sign is negative when end is before start.","sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."}}}}},"headers":{"X-RateLimit-Limit":{"description":"Requests allowed in the current one-minute window for this IP.","schema":{"type":"integer"}},"X-RateLimit-Remaining":{"description":"Requests remaining in the current window.","schema":{"type":"integer"}},"X-RateLimit-Reset":{"description":"Unix time when the window resets.","schema":{"type":"integer"}}}},"400":{"$ref":"#/components/responses/BadRequest"},"429":{"$ref":"#/components/responses/RateLimited"}}}},"/v1/business-days/roll":{"get":{"operationId":"roll_date","summary":"Roll to a business day","description":"If the date is already a business day, result is that date and rolled is false. Otherwise result is the nearest business day in direction next or previous. This is not Excel WORKDAY: add with days=1 always leaves the start date. This does not decide whether a filing is timely.","parameters":[{"name":"date","in":"query","required":true,"description":"The due date to roll.","schema":{"type":"string","pattern":"^\\d{4}-\\d{2}-\\d{2}$","description":"Civil date, YYYY-MM-DD. Not a timestamp."}},{"name":"direction","in":"query","required":true,"description":"next or previous. Other values, including forward, return 400 invalid_direction.","schema":{"type":"string","enum":["next","previous"]}},{"name":"calendar","in":"query","required":false,"description":"us-federal-opm: US federal offices (OPM Monday–Friday). This is the default when calendar is omitted. Saturday: Observed the preceding Friday (5 U.S.C. § 6103(b)(1)). Sunday: Observed the following Monday (Executive Order 11582 § 3(a)). Source: https://www.opm.gov/policy-data-oversight/pay-leave/federal-holidays/. us-fed-banking: Federal Reserve Banks and Branches. Saturday: Banks stay open the preceding Friday. The Board of Governors is closed that Friday. K.8. Sunday: Banks and the Board of Governors are closed the following Monday. K.8. Source: https://www.federalreserve.gov/aboutthefed/k8.htm. Unknown ids return 400 invalid_calendar.","schema":{"$ref":"#/components/schemas/CalendarId"}}],"responses":{"200":{"description":"The same date, or the nearest business day.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/RollResult"},"example":{"calendar":"us-federal-opm","date":"2026-07-03","direction":"next","rolled":true,"result":"2026-07-06","result_weekday":"Monday","reason":"observed federal holiday","convention":"If the date is a business day, result is that date. Otherwise result is the nearest business day in the requested direction. This is not Excel WORKDAY: add with days=1 always leaves the start date.","sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."},"examples":{"offices":{"summary":"2026-07-03 rolls to 2026-07-06 on the office calendar","value":{"calendar":"us-federal-opm","date":"2026-07-03","direction":"next","rolled":true,"result":"2026-07-06","result_weekday":"Monday","reason":"observed federal holiday","convention":"If the date is a business day, result is that date. Otherwise result is the nearest business day in the requested direction. This is not Excel WORKDAY: add with days=1 always leaves the start date.","sources":["5 U.S.C. § 6103(a) (legal public holidays; Juneteenth added by Pub. L. 117-17, June 17, 2021)","5 U.S.C. § 6103(b)(1) (Saturday holiday observed the preceding Friday for a Monday–Friday basic workweek)","Executive Order 11582 § 3(a) (Sunday holiday observed the next workday; Monday for a Monday–Friday basic workweek)","U.S. Office of Personnel Management, Federal Holidays (Monday–Friday observed dates). Tables for 2021–2030 checked 2026-10-17."],"disclaimer":"Observed dates match the OPM Monday–Friday federal holiday schedule. They do not cover compressed work schedules, other workweeks, agency-specific in-lieu-of days, state or local holidays, or stock-exchange holidays. Inauguration Day is identified for the Washington, DC area and is not a nationwide closing. Not legal, payroll, or financial advice."}},"banks":{"summary":"2026-07-03 stays put on the Reserve Bank calendar","value":{"calendar":"us-fed-banking","date":"2026-07-03","direction":"next","rolled":false,"result":"2026-07-03","result_weekday":"Friday","reason":"already a business day","convention":"If the date is a Reserve Bank business day, result is that date. Otherwise result is the nearest one in the requested direction. A Saturday holiday does not close Friday. This is not Excel WORKDAY: add with days=1 always leaves the start date.","sources":["Board of Governors, K.8 Holidays Observed by the Federal Reserve System, https://www.federalreserve.gov/aboutthefed/k8.htm (2026–2030 table, last update July 8, 2026, checked 2026-10-17). Saturday: Banks open the preceding Friday, Board of Governors closed. Sunday: Banks and the Board closed the following Monday.","K.8 as of 2022-06-30, captured 2022-07-01: 2022–2026 table. Sunday closings include June 20, 2022, December 26, 2022, and January 2, 2023. https://web.archive.org/web/20220701092245/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2022-12-30, captured 2023-01-19: 2023–2027 table, including Juneteenth. https://web.archive.org/web/20230119211335/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2024-01-05, captured 2024-06-14: 2024–2028 table. The New Year’s Day 2028 footnote is December 31, 2027. https://web.archive.org/web/20240614134448/https://www.federalreserve.gov/aboutthefed/k8.htm","K.8 as of 2021-01-04, harvested 2021-01-16: 2021–2025 table, published before Juneteenth. https://webharvest.gov/congress116th/20210116025255/https://www.federalreserve.gov/aboutthefed/k8.htm","Federal Reserve Board press release, June 17, 2021: payment services stayed open on Friday, June 18, 2021, because Juneteenth fell on Saturday. https://www.federalreserve.gov/newsevents/pressreleases/other20210617b.htm"],"disclaimer":"Weekday closings are the Federal Reserve Banks and Branches schedule from K.8. A Saturday holiday does not close the preceding Friday: the Banks stay open, and the Board of Governors in Washington is closed. A Sunday holiday closes the following Monday. This is not the OPM federal-employee schedule, not Inauguration Day, and not ACH or Fedwire operating hours. The October 9, 2025 announcement about later Fedwire Funds and National Settlement Service hours is not applied. Not legal, payroll, or financial advice."}}}}},"headers":{"X-RateLimit-Limit":{"description":"Requests allowed in the current one-minute window for this IP.","schema":{"type":"integer"}},"X-RateLimit-Remaining":{"description":"Requests remaining in the current window.","schema":{"type":"integer"}},"X-RateLimit-Reset":{"description":"Unix time when the window resets.","schema":{"type":"integer"}}}},"400":{"$ref":"#/components/responses/BadRequest"},"429":{"$ref":"#/components/responses/RateLimited"}}}}},"components":{"schemas":{"CalendarId":{"type":"string","enum":["us-federal-opm","us-fed-banking"],"default":"us-federal-opm"},"Error":{"type":"object","required":["error","message"],"properties":{"error":{"type":"string","enum":["unexpected_parameter","missing_parameter","invalid_parameter","invalid_calendar","invalid_date","invalid_year","invalid_days","invalid_direction","invalid_range","out_of_range","not_found","bad_request","method_not_allowed","rate_limited","internal"]},"message":{"type":"string"}}},"ServiceIndex":{"type":"object","required":["service","version","default_calendar","openapi","llms","mcp","mcp_manifest","mcp_server_card"],"properties":{"service":{"const":"bizday"},"version":{"type":"string"},"default_calendar":{"const":"us-federal-opm"},"openapi":{"const":"/openapi.json"},"llms":{"const":"/llms.txt"},"mcp":{"const":"/mcp"},"mcp_manifest":{"const":"/.well-known/mcp.json"},"mcp_server_card":{"const":"/.well-known/mcp/server-card.json"},"endpoints":{"type":"array"},"coverage":{"$ref":"#/components/schemas/Coverage"}}},"Health":{"type":"object","required":["ok","service","version"],"properties":{"ok":{"type":"boolean"},"service":{"const":"bizday"},"version":{"type":"string"},"calendar":{"const":"us-federal-opm"}}},"Coverage":{"type":"object","required":["from","to"],"properties":{"from":{"const":"2021-01-01"},"to":{"const":"2100-12-31"}}},"CalendarList":{"type":"object","required":["default","calendars"],"properties":{"default":{"const":"us-federal-opm"},"calendars":{"type":"array","items":{"$ref":"#/components/schemas/Calendar"}}}},"Calendar":{"type":"object","required":["id","name","source_url","saturday_rule","sunday_rule","coverage","last_verified","changelog","disclaimer"],"properties":{"id":{"$ref":"#/components/schemas/CalendarId"},"name":{"type":"string"},"default":{"type":"boolean"},"source_url":{"type":"string"},"sources":{"type":"array","items":{"type":"string"}},"coverage":{"$ref":"#/components/schemas/Coverage"},"last_verified":{"type":"string"},"saturday_rule":{"type":"string"},"sunday_rule":{"type":"string"},"changelog":{"type":"array"},"disclaimer":{"type":"string"}}},"Holiday":{"type":"object","required":["name","actual","observed","closes_weekday","shift_rule"],"properties":{"name":{"type":"string"},"actual":{"type":"string","pattern":"^\\d{4}-\\d{2}-\\d{2}$","description":"Civil date, YYYY-MM-DD. 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Not a timestamp."},"business_days":{"type":"integer"},"convention":{"type":"string"},"sources":{"type":"array","items":{"type":"string"}},"disclaimer":{"type":"string"}}},"RollResult":{"type":"object","required":["calendar","date","direction","rolled","result","reason","sources","disclaimer"],"properties":{"calendar":{"$ref":"#/components/schemas/CalendarId"},"date":{"type":"string","pattern":"^\\d{4}-\\d{2}-\\d{2}$","description":"Civil date, YYYY-MM-DD. Not a timestamp."},"direction":{"type":"string","enum":["next","previous"]},"rolled":{"type":"boolean"},"result":{"type":"string","pattern":"^\\d{4}-\\d{2}-\\d{2}$","description":"Civil date, YYYY-MM-DD. Not a timestamp."},"result_weekday":{"type":"string"},"reason":{"type":"string"},"convention":{"type":"string"},"sources":{"type":"array","items":{"type":"string"}},"disclaimer":{"type":"string"}}}},"responses":{"BadRequest":{"description":"The query was rejected. No date was guessed. error is a stable code and message says what to fix.","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"},"example":{"error":"invalid_calendar","message":"calendar must be one of: us-federal-opm, us-fed-banking."}}}},"RateLimited":{"description":"Preview limit is 60 requests per minute per IP. Retry-After is in seconds. GET /v1, GET /v1/health, GET /openapi.json, GET /llms.txt, GET /.well-known/mcp.json, and GET /.well-known/mcp/server-card.json do not count. MCP tool calls do.","headers":{"Retry-After":{"schema":{"type":"integer"},"description":"Seconds to wait."},"X-RateLimit-Limit":{"description":"Requests allowed in the current one-minute window for this IP.","schema":{"type":"integer"}},"X-RateLimit-Remaining":{"description":"Requests remaining in the current window.","schema":{"type":"integer"}},"X-RateLimit-Reset":{"description":"Unix time when the window resets.","schema":{"type":"integer"}}},"content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"},"example":{"error":"rate_limited","message":"Preview limit is 60 requests per minute per IP. Retry after 1 seconds."}}}}}}}