Date Math
The Date Calculator, Add Days to Date, and Subtract Days From Date tools let you move forward or backward from any date. For work-specific date math, the Business Days and Workdays calculators exclude weekends (and holidays, for Business Days) when counting the days between two dates — useful for shipping estimates, SLAs, and payroll. The Week Number and Leap Year calculators answer specific calendar questions, and Days Until Countdown and the Birthday Calculator count down to a specific future date.
Clocks & Timers
The Online Alarm Clock, Online Stopwatch, and Pomodoro Timer run right in your browser for studying, workouts, or focused work sessions, while the Time Zone Converter and Time Duration Calculator handle time-of-day math rather than calendar dates.