|Enter latitude in decimal
northern latitudes positive, southern negative,
and hit RETURN key.
Enter longitude in decimal degrees:
eastern longitudes positive, western negative,
and hit RETURN key.
|Select your time zone:
east of Greenwich positive, west of Greenwich negative.
||You may use the keys "h",
"d", "m", "n" to increase the hour, date, month, or
or shift key and "h", "d", "m" , "n" to decrease the hour, date, month, or minute !
Click the applet first !
|The Local Solar Time is
12:00 when the Sun crosses the north-south meridian
reaching its highest point in the sky (measured by a
sundial). It differs from local standard time
according to longitude, time zone, and equation of
The Local Hour Angle (LHA) of a heavenly body is the angular distance from the observer's meridian to the local meridian of the body, measured on the celestial equator westward from the local meridian through 360°, normally expressed in time-units (h, m, s).
Both clocks of my applet are using the local hour angle (of the Sun or the Moon):
The clock time is 12:00 at upper transit, and 0:00 at lower transit (minimum altitude).
The gray sectors are given by the times of rise and set, also using the local hour angle.
A lunar day (also called tidal day) is the time required for the earth to rotate once with respect to the moon, or the interval between two successive upper transits of the Moon over the meridian of a place. The mean lunar day is approximately 24 hours and 50.4 minutes (24.84 solar hours) in length, or 1.035 times as great as the mean solar day.
Conversion of standard time to local solar time:
Example: Berlin, time zone UT+1h, longitude 13.41° E,
on 2007 Mar 24 at 22:28 standard time (CET).
The correction for longitude is 4 minutes per degree of difference between the local longitude (13.41° E) and the longitude of the standard time meridian (UT+1h is corresponding to 15° E):
equation of time
4*(13.41-15) min =
-6.36 min = -6 min 22 s
-6 min 16 s
- 12 min 38 s =
in 2007: variation between 24 h 38.5 min (Jan 9/10) and 24 h
66.5 min (Nov 25/26)
2007 avarage: 24 h 50.446 min = 24.8408 h
2007-2037 avarage: 24 h 50.471 min = 24.8412 h
Moon" from the "Details" menu:
far, the Moonlight diagram is not working correctly for high
latitudes > 61.4° = 90° -(23.44°+5.14°),
where the Moon can be visible/unvisible for several days.
"Lunar Transits" from the "Details" menu.
Table: select "Full Moon" from the "Details" menu.
Moon on 2007, Apr 2 at 17:16 UT
Aluna - the
world's first tidal powered Moon Clock
Franciscus Milliet Dechales: Cursus seu mundus
of the Moon (Astronomy Picture of the Day)