Date & Time Calculator

1 Days Between Dates

Start date

End date

Count both start and end dates

Select two dates.

Date of birth

Age on date

Enter a birth date.

Starting date

Operation

Number of days

Enter a starting date and number of days.

Date

Select a date.

Target date & time

Optional event name

00d 00h 00m 00s

Date & time

From time zone

To time zone

Choose a date/time and two time zones.

Uses the browser's IANA time-zone database, including historical and daylight-saving rules.

Date & local time → Unix timestamp

Unix timestamp will appear here.

Unix timestamp → Date & time

Date will appear here.

Date

Time zone

Comparison year

Select a date and time zone.

DST detection compares the selected date's UTC offset with January and July offsets for that zone/year.

Start date

End date

Include start and end dates Exclude listed holidays Optional holidays to exclude — one YYYY-MM-DD date per line

Counts Monday through Friday, with optional holiday exclusions.