Date & Time Calculators

Dates are the arithmetic people most often do wrong by hand, because months have different lengths, leap years are irregular, and adding hours and minutes is base sixty while the decimal hours on a timesheet are base ten. Every calculator here uses the browser's own calendar, so leap years, month lengths and the transition dates are all handled correctly.

Between two dates

The date calculator gives the gap between two dates in years, months, weeks and days at once. The business days calculator counts only working days and lets you exclude holidays, which is what deadlines and contracts actually run on. The age calculator is the same arithmetic aimed at a birthday, and the age difference calculator compares two people.

Adding and subtracting

Use the add or subtract days calculator for "ninety days from today", with an option to count in working days only. The days until a date calculator is the countdown version, and the week number calculator answers the ISO week question that reporting calendars run on.

Clock time and timesheets

The time duration calculator works out the gap between two times, including shifts that cross midnight. The work hours calculator turns a week of start and finish times into paid hours with breaks and overtime, and the hours calculator and 24-hour time converter handle the conversions around them.