Date & Time

Convert between Unix timestamps and human-readable dates in any timezone.

Build and parse cron expressions with a visual editor and next-run preview.

Convert times between any two timezones with DST awareness.

Calculate the exact difference between two dates in days, months, years, and more.

Calculate exact age in years, months, and days from a date of birth, plus total days lived and days until your next birthday.

See the current time in multiple timezones at once, with a searchable list of every IANA timezone — updates live, no server call.

Find the ISO 8601 week number for any date, plus its ISO week year, day-of-year, and the exact Monday–Sunday range of that week.

Add or subtract a list of HH:MM:SS time durations — like video clip lengths or work time logs — and get the running total in HH:MM:SS, total seconds, and decimal hours.

Check whether any year is a leap year under the Gregorian calendar rule, with a plain-English explanation of why, plus a list of nearby leap years.

Count business days (Monday-Friday) between two dates, or add a number of business days to a starting date, excluding weekends and any custom holiday dates.