Measures: Time — how long something takes
Second
The base unit of time — every clock on Earth counts these.
TimeHow it's defined
Since 1967, one second is 9,192,631,770 oscillations of the microwave radiation from a cesium-133 atom — an atomic tick that never drifts. Every other unit of time is built on it.
Convert — honestly
0.0166666667 min
Minute · factor exact — exact by definition
0.000277777778 h
Hour · factor exact — exact by definition
0.0000115740741 d
Day · factor exact — exact by definition
Conversions run through the second using the stated factors — no rounding beyond display precision, and every factor says whether it's exact or measured.
Where you meet it
- Timii — every tracked hour is 3,600 of these ↗ open timii
- GPS satellites, whose clocks must agree to billionths of a second for your map dot to be right
Other ways to measure time
Source
This page is an authored summary of the authoritative definition — checkable one click away.
BIPM — The International System of Units (SI Brochure, 9th ed.)