Article · Wikipedia archive · Last revised Jun 22, 2026

Hexadecimal time

Hexadecimal time is the representation of the time of day as a hexadecimal number in the interval [0, 1].

Last revised
Jun 22, 2026
Read time
≈ 2 min
Length
455 w
Citations
2
Source
UTC-00:00 Hex Triplet (Update)
Base 60 04:02:28
Base 16

2B_1A_ED

Nystrom's tonal clock-face. The proposed figures on the right are based on rotations of those on the left (assigning value 10 to symbol 9). source ↗
A hexadecimal clock-face (using the Florence meridian) source ↗

Hexadecimal time is the representation of the time of day as a hexadecimal number in the interval [0, 1].

The day is divided into 1016 (1610) hexadecimal hours, each hour into 10016 (25610) hexadecimal minutes, and each minute into 1016 (1610) hexadecimal seconds.

History

This time format was proposed by the Swedish-American engineer John W. Nystrom in 1863 as part of his tonal system.1

In 1997, the American Mark Vincent Rogers of Intuitor proposed a similar system of hexadecimal time and implemented it in JavaScript as the Hexclock.2

Implementation

A day is unity, or 1, and any fraction thereof can be shown with digits to the right of the hexadecimal separator. So the day begins at midnight with .0000 and one hexadecimal second after midnight is .0001. Noon is .8000 (one half), one hexadecimal second before was .7FFF and one hexadecimal second before next midnight will be .FFFF.

Hexadecimal time may also be formatted with an underscore separating hexadecimal hours, minutes and seconds; in full mathematical format this follows hex triplet web color scheme.

Hex Hex (Boardman) ISO 8601 Comment
.0100 0_10_0 00:05:37.5
.0200 0_20_0 00:11:15
.0400 0_40_0 00:22:30
.0800 0_80_0 00:45:00
.1000 1_00_0 01:30:00 1.5:24 = 1:16 = 0.1
.8000 8_00_0 12:00:00 12:24 = 8:16 = 0.8
.F000 F_00_0 22:30:00 22.5:24 = 15:16 = 0.F
.F800 F_80_0 23:15:00

Conversions

Hex hexsec
base 16
hexsec
base 10
Traditional
1 day = 10000 = 65536 = 24 h
1 hexadecimal hour = 1000 = 4096 = 1 h 30 min
1 hexadecimal tertiary = 100 = 256 = 5 min 37.5 s
1 hexadecimal minute = 10 = 16 = 21.09375 s
1 hexadecimal second = 1 = 1 = 1.318359375 s
1 second = 0.C22E4 = 0.75851 = 1 s
See also

See also

References

References

Further reading

Further reading

External links