Time Calculators
Time duration and time-sheet calculators.
About these calculators
Six time calculators for payroll, billing and scheduling arithmetic: hours worked with overnight-shift wraparound handled correctly, decimal-versus-hours-minutes output for payroll systems, duration between timestamps across midnight, and world-clock conversions with daylight-saving applied from current rules.
Shift arithmetic is the hard part and gets explicit attention: a 10 pm-to-6 am shift spans two calendar days and the calculators treat that as ordinary rather than exceptional. Time-card totals weekly hours with overtime thresholds visible so pay disputes can be checked line by line.
Choosing the right calculator
Work hours and payroll
Hours and time-card total daily and weekly worked time with break deductions; work-hours handles shift patterns including overnight spans; outputs appear in both HH:MM and decimal hours because payroll software insists on decimals while humans read clocks.
Durations and zones
Time-duration measures elapsed time between any two timestamps; time adds or subtracts durations from clock times for countdowns and ETAs; time-zone-converter aligns meetings across cities with DST correctness — essential when scheduling across India's single zone and multi-zones abroad.
Time calculators we stand behind
Time Calculator
Add or subtract hours and minutes from any time of day. Handles midnight wrap-around and reports the day shift.
Time Duration Calculator
Calculate the duration between two times or two date-times in hours, minutes and seconds — including overnight shifts. Free and instant.
World Time Zone Converter (IST, EST & GMT)
Convert times between 40+ world cities with 12-hour and 24-hour formats and day-shift flags. Ideal for IST to EST, IST to GMT and calls.
Also available (3) — work in progress, not yet indexed
These calculators work but are still being checked for accuracy and sourcing, so they are not in search yet. They are free to use.