Polystash Business Days API

API reference

Public holidays and business-day arithmetic for 200+ countries and territories, with regional coverage: state, province and canton level holidays for 20 countries via ISO 3166-2 subdivision codes. Calendars are precomputed for 2000 through 2060 from curated open data. Every country in GET /countries carries a coverage flag (full or partial) so you can tell where the national list is known to be incomplete.

Base URL: https://api.polystash.com. Machine-readable spec: /openapi.json.

Authentication

Requests go through RapidAPI. Send your RapidAPI key on every request as the X-RapidAPI-Key header, together with the X-RapidAPI-Host header for this API. RapidAPI forwards the call and counts it against your plan. 

X-RapidAPI-Key: YOUR_RAPIDAPI_KEY
X-RapidAPI-Host: api.polystash.com

Keys are issued and rotated on RapidAPI: Subscribe on RapidAPI.

The coverage field

Is coverage the same for every country?

No, and the API says so. Every entry in /countries carries a coverage field: full means the national list is complete and reviewed through 2060; partial means the national list is known to be incomplete or lunar-calendar holidays are missing for some years. India, Thailand and Malaysia are partial today and are being upgraded. Check the flag before relying on a country for payroll or legal deadlines.

Endpoints

GET /countries

List supported countries

Example response

[
  {
    "code": "DE",
    "name": "DE",
    "regionCount": 16,
    "coverage": "full"
  },
  {
    "code": "IN",
    "name": "IN",
    "regionCount": 35,
    "coverage": "partial"
  },
  {
    "code": "US",
    "name": "US",
    "regionCount": 37,
    "coverage": "full"
  }
]

Example request

curl -H 'X-RapidAPI-Key: YOUR_RAPIDAPI_KEY' \
     -H 'X-RapidAPI-Host: api.polystash.com' \
     'https://api.polystash.com/countries'

GET /v1/holidays/{country}/{year}

Holidays for a country and year

NameInRequiredDescriptionExample
country path yes US
year path yes 2026
region query no ISO 3166-2 subdivision code, e.g. US-TX US-TX
type query no Comma-separated holiday types: public,bank,school,authorities,optional,observance. Matches any requested type (OR); whitespace is trimmed. Takes precedence over types when both are supplied. public,optional
types query no Alias for type: comma-separated holiday types with OR semantics. Used only when type is absent.
lang query no Preferred name language (falls back to English) local

Example request

curl -H 'X-RapidAPI-Key: YOUR_RAPIDAPI_KEY' \
     -H 'X-RapidAPI-Host: api.polystash.com' \
     'https://api.polystash.com/v1/holidays/US/2026?region=US-TX&type=public%2Coptional&lang=local'

GET /v1/holidays/{country}/{year}.ics

iCalendar holidays for a country and year

RFC 5545 VCALENDAR with one all-day VEVENT per holiday on its observed date. English SUMMARY, local name and types in DESCRIPTION, exclusive next-day DTEND, and UID <id>@polystash.com. Uses CRLF and UTF-8 lines folded at 75 octets.

NameInRequiredDescriptionExample
country path yes DE
year path yes 2027
region query no ISO 3166-2 subdivision code; includes nationwide holidays DE-BY

Example request

curl -H 'X-RapidAPI-Key: YOUR_RAPIDAPI_KEY' \
     -H 'X-RapidAPI-Host: api.polystash.com' \
     'https://api.polystash.com/v1/holidays/DE/2027.ics?region=DE-BY'

GET /v1/holidays/{country}.ics

iCalendar holidays over a range of years

Same all-day VEVENT format as the year feed. Defaults to the current UTC year through current year + 2. The range is inclusive and may contain at most five years. Years absent from the country data contribute no events.

NameInRequiredDescriptionExample
country path yes US
from query no First year, inclusive; defaults to the current UTC year 2027
to query no Last year, inclusive; defaults to current UTC year + 2 2029
region query no ISO 3166-2 subdivision code; includes nationwide holidays US-TX

Example request

curl -H 'X-RapidAPI-Key: YOUR_RAPIDAPI_KEY' \
     -H 'X-RapidAPI-Host: api.polystash.com' \
     'https://api.polystash.com/v1/holidays/US.ics?from=2027&to=2029&region=US-TX'

GET /v1/businessdays/sla

Calculate an SLA deadline in business days or working hours

All arithmetic uses local wall-clock dates in start's fixed offset; no DST adjustment. Uses the country's weekend and country/region holidays. For days, first roll a non-business start to the next business day at dayStart, then advance offset business days, preserving time. For hours, snap to a working period and count only within [dayStart, dayEnd), carrying remainder forward; a deadline may equal dayEnd. Missing calendar years have no known holidays.

NameInRequiredDescriptionExample
country query yes DE
region query no DE-BY
start query yes ISO 8601 YYYY-MM-DDTHH:MM[:SS[.sss]] followed by Z or +/-HH:MM. Seconds are optional; up to three fractional digits. Encode a positive offset's + as %2B. 2027-03-05T16:40:00+01:00
offset query yes Positive safe integer in decimal digits. Deadlines beyond ISO year 9999 return INVALID_OFFSET. 2
unit query yes hours
dayStart query no Opening time; must precede dayEnd
dayEnd query no Exclusive closing time; overnight windows are not supported

Example request

curl -H 'X-RapidAPI-Key: YOUR_RAPIDAPI_KEY' \
     -H 'X-RapidAPI-Host: api.polystash.com' \
     'https://api.polystash.com/v1/businessdays/sla?country=DE&region=DE-BY&start=2027-03-05T16%3A40%3A00%2B01%3A00&offset=2&unit=hours'

GET /v1/businessdays/add

Add N business days to a date

NameInRequiredDescriptionExample
country query yes US
date query yes 2026-07-02
days query yes Positive or negative, non-zero 10
region query no US-TX

Example request

curl -H 'X-RapidAPI-Key: YOUR_RAPIDAPI_KEY' \
     -H 'X-RapidAPI-Host: api.polystash.com' \
     'https://api.polystash.com/v1/businessdays/add?country=US&date=2026-07-02&days=10&region=US-TX'

GET /v1/businessdays/between

Count business days between two dates

NameInRequiredDescriptionExample
country query yes DE
start query yes 2026-12-20
end query yes 2027-01-10
region query no

Example request

curl -H 'X-RapidAPI-Key: YOUR_RAPIDAPI_KEY' \
     -H 'X-RapidAPI-Host: api.polystash.com' \
     'https://api.polystash.com/v1/businessdays/between?country=DE&start=2026-12-20&end=2027-01-10'