Add or subtract time values. Input fields can be left blank (taken as 0).
Calculate the resulting date and time by adding or subtracting days, hours, minutes, and seconds from a start date.
Enter time values in the form of an expression. Each value has a number followed by d (days), h (hours), m (minutes), or s (seconds). Only + and − operators are accepted.
Adding and subtracting time uses a base-60 system for minutes and seconds and base-24 for hours. When values exceed their unit limit they carry over automatically. This calculator handles all conversions without manual adjustments.
The expression calculator accepts natural input using d (days), h (hours), m (minutes), and s (seconds). For example: "2h 30m + 1h 45m" returns the total. Only addition and subtraction are supported.
Adding a duration to a starting date and time is useful for scheduling, deadline calculation, and determining end times for events and processes that span multiple hours or days.
This calculator operates on local time and does not account for time zone changes or daylight saving transitions. For calculations that span these boundaries, verify results with a dedicated time zone tool.