Hexadecimal time

GMT at page generation (Update)
24-hour time18:56:56
Hexadecimal time.CA1F
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).
A hexadecimal clock-face (using the Florence meridian)

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.


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]


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.

Intuitor-hextime may also be formatted with an underscore separating hexadecimal hours, minutes and seconds. For example:


HexHex (Boardman)ISO 8601Comment
.10001_00_001:30:001.5:24 = 1:16 = 0.1
.80008_00_012:00:0012:24 = 8:16 = 0.8
.F000F_00_022:30:0022.5:24 = 15:16 = 0.F


base 16
base 10
1 day=10000=65536=24 h
1 hexadecimal hour=1000=4096=1 h 30 min
1 hexadecimal maxime=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


  1. ^ Nystrom, John William (1862). Project of a New System of Arithmetic, Weight, Measure and Coins: Proposed to be Called the Tonal System, with Sixteen to the Base. Lippincott. p. 105.
  2. ^ "Intuitor Hex Headquarters, The Hex Clock". www.intuitor.com. Retrieved 2020-04-02.

External links

Media files used on this page

Wooden hourglass 3.jpg
Author/Creator: User:S Sepp, Licence: CC-BY-SA-3.0
Alternative version of image:Wooden hourglass 2.jpg. Wooden hourglass. Total height:25 cm. Wooden disk diameter: 11.5 cm. Running time of the hourglass: 1 hour. Hourglass in other languages: 'timglas' (Swedishrtrttttyo), 'sanduhr' (German), 'sablier' (French), 'reloj de arena' (Spanish), 'zandloper' (Dutch), 'klepsydra' (Polish), 'přesýpací hodiny' (Czech), 'ampulheta' (Portuguese).
Hexadecimal Clock by Nystrom.jpg
Hexadecimal Clock, published in 1862 by John W. Nystrom as a part of his "tonal system" proposal - the attempt to replace the decimal by the hexadecimal system
Hexadecimal clock