# Hexadecimal time

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

The day is divided into 10_{16} (16_{10}) hexadecimal hours, each hour into 100_{16} (256_{10}) hexadecimal minutes, and each minute into 10_{16} (16_{10}) hexadecimal seconds.

## History

Hexadecimal time may have been used during the Tang Dynasty (7th – 10th centuries) in China.

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

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

## The system of Rogers

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:

### Clock

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 maxime | = | 100 | = | 256 | = | 5 min 37.5 sec |

1 hexadecimal minute | = | 10 | = | 16 | = | 21.09375 sec |

1 hexadecimal second | = | 1 | = | 1 | = | 1.318359375 sec |

1 second | = | 0.C22E4 | = | 0.75851 | = | 1 sec |

## See also

## References

## External links

- Hexadecimal Time Applet - with digital and analogue representations.
- Hexclock - local time as a hexadecimal number
- True Binary Time - local time as a binary number
- Analogue hexadecimal clock - Florence Mean Time
- Geektime.org - different approach, based on "hex-seconds"