Date & time

Date difference, age, business days, date math and time zones

Convert Unix timestamps to dates and back, in seconds or milliseconds, with local, UTC, ISO and relative output.

Find the difference between two dates in days, weeks and calendar years, months and days — great for countdowns and project timelines.

Calculate your exact age and total days from a birth date, plus a countdown to the next birthday.

Count business days between two dates, excluding weekends, with support for custom holidays.

Add or subtract days, weeks, months or years from a date, with correct month-end and leap-year handling.

Convert a time between common time zones, with UTC, a Unix timestamp and a quick seven-city reference.