Astronomical Time
By Larry McNish

Longitude: Deg: Min: Sec: West East     Night Vision Mode

Changing any longitude value automatically saves it in a "cookie" for use next time.

Local PC Time
Coordinated Universal Time (UTC)

Local Sidereal Time (LST)

(LST based on Longitude setting)

Greenwich Sidereal Time (GST)

(UTC and GST are based on PC settings)
Julian Date

The accuracy of the displays depends on the correct PC time setting, the correct PC Time Zone setting, and the correct Longitude setting.
To set your PC clock accurately you can use an Internet Time Service

Some of the JavaScript used to calculate these values was written by and is Copyright © Peter Hayes 2001-2016.
His website can be found at
Copyright 2004-2016, Larry McNish All rights reserved.
Page last updated: Feb 2, 2016