Date & Time
Calculate durations, business days, countdowns, and convert time zones. Private, client-side, and simple.
Time Duration Calculator
Calculate the hours, minutes, and seconds difference between two times.
Date Difference Calculator
Calculate the exact span between two calendar dates.
Working Days Calculator
Calculate total weekdays, weekends, and holidays between two dates.
Countdown Calculator
Display a real-time countdown to a specific date and time.
Date Calculator
Add or subtract days, weeks, months, or years to/from a starting date.
Stopwatch
A high-precision stopwatch with multi-lap recording.
Timer
A countdown timer with preset quick-shortcuts and synthesized audio alerts.
Calendar Generator
Generate and print custom monthly or yearly calendars.
Leap Year Checker
Check if a year is a leap year based on Gregorian rules.
Age Difference Calculator
Calculate the exact age difference between two people.
Business Days Calculator
Calculate business days between dates or adjust dates excluding weekends and holidays.
Time Zone Converter
Convert date and clock times between multiple global time zones.
Week Number Calculator
Calculate the ISO-8601 week number, day of the week, and day of the year.