Date & Time Calculators

Time math without the mistakes. Count working days for deadlines, convert meeting times across time zones, add or subtract from dates, turn timesheets into decimal hours, and decode Unix timestamps. Everything runs on real calendar rules — leap years, month lengths and daylight saving handled correctly.

Working Days CalculatorBusiness days between two dates, minus weekends and holidays. Days Until CalculatorCountdown to any date in days, weeks and months. Work Hours CalculatorClock-in to clock-out, minus breaks — in hh:mm and decimal. Time Zone ConverterConvert meeting times across world time zones, DST included. Week Number CalculatorISO week number for any date. Day of the Week CalculatorWhat weekday any date falls on — past or future. Date Add & Subtract CalculatorAny date ± days, weeks, months or years. Sleep CalculatorIdeal bedtimes and wake times based on 90-minute cycles. Time to Decimal CalculatorHH:MM ↔ decimal hours, both directions. Unix Timestamp ConverterEpoch seconds ↔ human dates, local and UTC. Leap Year CalculatorCheck any year, with the century-rule explained. Military Time Converter24-hour ↔ AM/PM, with midnight and noon done right. Add & Subtract Time CalculatorClock time ± hours and minutes, across midnight.