A simple Clock in Java

When loaded, the applet will appear in its own window.

Hours/Day
- 12
- 24
Time-Scale
- UTC (Universal Coordinated Time; a.k.a. Greenwich Mean Time (GMT))
- LMT (Local Mean Time; a.k.a. just plain normal civil time)
- GMST (Greenwich Mean Sidereal Time -- "star time" at Greenwich)
- LMST (Local Mean Sidereal Time -- the local "star time")
The View
- Time (a normal, analogue clock)
- North or South (a planispheric star-map, centered on either the North or South celestial pole)
Update Period
- By entering a number between 1 and 59, and pressing [Secs] you can set the update rate (in seconds) for the UTC and LMT time-scale displays.
Magnitude
- Selecting one of the "M: #.#" radio-buttons loads a star catalog with the specified limiting magnitude. (This may take awhile.)

For LMST to be correct you must enter your correct longitude.
The North and South views show the entire sky -- even any portion which may be below your horizon. The yellow line denotes the meridian from the North (South) pole at the center, to almost the South (North) pole at the lower edge.
Selecting the LMST time-scale and the North or South view should display a map of what the sky looks like outside your window right now! (Assuming it's night, and clear, and that you have a window.)

Jeff Mallatt
15 Allen St., No. 2
Arlington, MA 02474-6809
(781) 641-3327 (day/eve)
Last Updated: 27 Oct 2003