Parse dates · Count days · Calendar detail
Date API
From written dates
to useful answers.
Turn dates from forms, spreadsheets and logs into a consistent ISO date. Validate the day, count the days between dates and add calendar detail when you need it.
Start free. Calendar detail included on every plan.
Try it
A useful answer in one call
Dates in.
Clear JSON out.
Parse a date, compare two days or read the calendar facts. Choose a task to see its request and complete response.
One date your app can use.
Normalize a written date to YYYY-MM-DD, with validity and a Unix timestamp in seconds.
Request
curl "https://api.parseapi.com/date/March%2029,%202026?deep=true" \
-H "X-API-Key: YOUR_API_KEY"Example response
Date parsing and validation
Different formats.
One calendar day.
Normalize dates before you store, sort or compare them. Use ISO, English month names, numeric dates or compact dates with a four-digit year.
Supported formats- March 29, 2026
- 29 March 2026
- 3/29/2026
- 20260329
2026-03-29
YYYY-MM-DD
Ambiguity stays visible.
03/04/2026 has two valid readings. It returns valid: false until you choose the month-first or day-first format your input follows.
Impossible dates are caught.
February 30 returns valid: false with a null timestamp. Keep unresolved rows for review while the valid dates move into your app.
Date differences
The days between.
Already counted.
Count down to an event, measure a subscription window or compare dates from different formats. Add to= for the signed number of calendar days.
Use bare /date?to= to count from today in UTC.
118 days
Reverse the dates for -118. The same day returns 0.
Optional calendar detail
From a date
to your next report.
Group records by weekday, ISO week or quarter. Add deep=true to the same request for the calendar detail behind the date.
Included on every plan.
- Weekdays for schedules
- The weekday number and English name, with Monday as day 1.
- Weeks for reporting
- The ISO week and week-year, including weeks that cross New Year.
- Calendar facts for your app
- Month, quarter, day of year, leap-year status and days in the month.
One integration
Clean dates.
Where you need them.
Call Date over HTTP, use your language's SDK or connect through MCP. The same API key works across ParseAPI.
Clean a CSV of mixed datesFrom the first request to your application.
Copy a request above. The reference covers supported input, optional detail and error responses.
Use Time to convert between timezones, or Holiday to check the public holidays on your calendar.
Before you build.
Which date formats are supported?
ISO dates, English month names in either order, numeric dates with slashes, dots or hyphens, and eight-digit compact dates. Examples include March 29, 2026, 29 Aug 2026, 3/29/2026 and 20260829. Use four-digit years from 1000 to 9999.
How do ambiguous dates work?
If more than one real date fits, the response has valid: false and unix: null. Add format=mdy for month-first input or format=dmy for day-first input. ISO dates and spelled month names keep their own reading.
What happens to invalid dates?
An impossible, unsupported or ambiguous date returns HTTP 200 with valid: false. The date field echoes the input with whitespace normalized, and unix is null. With Deep, calendar detail is null too. A two-digit year does not resolve.
How do I count days between two dates?
Add to= to the first date. August 29 to December 25, 2026 returns days: 118. Future dates are positive, past dates are negative, and the same date returns zero. These are calendar days. For workdays, use the business days calculator.
Can I count from today?
Yes. GET /date?to=2026-12-25 counts from today in UTC. Bare GET /date returns today in UTC.
How are timestamps and timezones handled?
unix is seconds at midnight UTC for the parsed calendar date. A leading weekday and an ISO time tail are ignored. The Date API reads the written day. Use Time when you need a timezone conversion.
What does calendar detail include?
deep=true adds year, month and its English name, day, ISO weekday and its English name, ISO week and week-year, day of year, quarter, leap-year status and days in the month. ISO weeks start on Monday. Near New Year, the week-year can differ from the calendar year.
Is Deep included in the free Date API?
Parsing and date differences are available on every plan. New accounts need a paid plan for calendar Deep. Existing accounts keep their current Deep access. Each call uses one API request from your monthly allowance.
Count workdays with the business days calculator. Choose your calendar and which dates to include.
Date API pricing
Make dates work
in your app.
Start free. Parsing, date differences and calendar detail use the same request allowance, shared across ParseAPI products.
Free
Start with a free API key.
Room to grow
Choose your capacity on Plans.