Time Calculator for Developers

Seconds to sane units, sprint arithmetic, ISO 8601 and epoch output — the time math you keep re-deriving in a REPL.

Current date & timeWork Day (8h)
YearMonthWeekDay
HourMinuteSecondTime separator (HH:MM:SS)
AMPMDate separator (MM/DD/YYYY)
Open the full app — it's free

Every developer has typed 86400 into a calculator to remember what a day is. TCalc knows: durations parse from any unit and format to any other — seconds, minutes, hours, days, timecode, ISO 8601, Unix epoch.

The developer layout below ships with the units you actually use; deadline math like "sprint minus time burned" is a single expression.

Real Examples

14d - 3d 4h=10D 20h

Sprint remaining after three days and change of work.

10000s=2h 46m 40s

That timeout value, in human units.

1000000s=≈ 11.57 days

A million seconds, converted with one keypress.

1D=1440m

Days to minutes — or seconds, or milliseconds.

Frequently Asked Questions

How do I convert seconds to hours and minutes?

Type the value with its unit: 10000s displays as 2h 46m 40s in compact format, or as 2.7778h in decimal hours. No dividing by 3600 in your head.

Does TCalc output ISO 8601 or Unix timestamps?

Yes — datetime results can be formatted as ISO 8601 or Unix epoch, and durations down to milliseconds. Switching formats is instant.

Can I do date arithmetic for deadlines?

Yes: subtract dates to get the gap (2026-12-24 − 2026-07-17 = 159 days) or subtract burned time from a sprint: 14d − 3d 4h = 10D 20h.