Date & Time
Time zones, durations and timestamps.
Age Calculator
Calculate exact age in years, months, days and hours.
Calendar Week Grid
Render a month grid with ISO week numbers.
Countdown Timer
Live countdown to any future date and time.
Date Add / Subtract
Add or subtract days, weeks, months or years from any date.
Date Difference Calculator
Difference between two dates in every common unit.
Date Format Converter
Parse any date input and format it with a custom pattern.
Day of the Week Finder
Find the day of the week, day of year and ISO week for any date.
Duration Formatter
Format seconds or milliseconds as readable durations.
ISO 8601 Duration Parser
Parse ISO 8601 duration strings into component parts.
Moon Phase Calculator
Estimate the moon phase and illumination for a date.
Recurring Event Calculator
Generate recurring event dates from a start date and interval.
Relative Time Formatter
Turn two timestamps into a friendly relative time phrase.
Stopwatch
Start / stop / lap stopwatch with millisecond precision.
Time Zone Converter
Convert any date and time between time zones.
Working Days Calculator
Count business days (Mon–Fri) between two dates.
World Clock
Live current time in cities around the world.