Universal Time Day Timescale

Range

The Univeral Time Day (UTD) timescale covers just one day of 24 hours.

Purpose

The UTD timescale is used in the layout of sundial faces where the noon hour point is to be adjusted to account for the difference between local mean solar time and timezone mean solar time.

Function

UTD times may be calculated using the sdUTDx function.

Definition

00:00:00 UT = 0 UTD
01:00:00 UT = 0.041666... UTD

and so on, and

23:59:59:99999 UT = .999999999988425926 UTD