Date calculators

Durations use civil UTC dates (year-month-day) to avoid daylight-saving shifts. A “day” here is a calendar date, not 24 astronomical hours.

Age in years, months and days depends on month lengths. Two tools answer two common questions: a detailed gap, and a plain day count.

Most used

Subcategories

Age

Age on a given date and next birthday.

Gaps and business days

Calendar days, weekends and statutory holidays.

Calendar

Adding days, day of the week, week number and leap years.

Full list

Questions

Is 29 February handled?

Yes. If the person was born on 29 February and the target year is not a leap year, the next birthday is placed on 28 February.