Sidereal Time Calculator For Any Date, Time and Longitude
PHP Program by Jay Tanner
Local Date
±
Y M D (Neg=BC)
Local Time
HH MM SS (00 to 24h)
Local Time Zone Offset
HH MM (Neg/Pos = W/E)
ΔT (Delta T)
±
HMS
UT
2460707.5
0.210277777778
-0.208333333333
+0.000000000000
Calendar Mode:
Julian
Gregorian
Longitude:
±Deg.ddd or ±D M S (Neg=W)
-76.8233097222
IMPORTANT:
Make sure that the local time, time zone and longitude are correctly matched for the location.
Optional NASA Polynomial ΔT estimate = +75 sec = +00h 01m 15s
Double-Click Within Text Area to Select ALL Text
SIDEREAL TIME FOR GIVEN DATE, TIME AND LONGITUDE Local Date = 2025 Feb 01 [Saturday] Gregorian JD Number = 2460708 JD00 = 2460707.5 = JD for 00h of date Local Time = 05:02:48 = 0.210277777778 day T Zone Diff = -05:00 = -0.208333333333 day Delta T = +00:00:00 = +0.000000000000 day Astronomical Julian Date: JDTT = JDNum - 0.5 + LTFrac - (TZFrac) + (dTFrac) = 2460707.918611111111 Longitude = -76° 49' 23.915" = -76.8233097222° (W) = -05h 07m 17.594s = -5.1215539815 h ================================================================= Local Mean Sidereal Time at Longitude -76.8233097222° (W) 13h 42m 58.543s = 13.7162619760 h 205° 44' 38.15" = 205.7439296395° Local True Sidereal Time at Longitude = -76.8233097222° (W) 13h 42m 58.636s = 13.7162877702 h 205° 44' 39.54" = 205.7443165530° Greenwich Mean Sidereal Time 18h 50m 16.137s = 18.8378159575 h 282° 34' 02.062" = 282.5672393618° Greenwich True Sidereal Time 18h 50m 16.230s = 18.8378417517 h 282° 34' 03.455" = 282.5676262753° ================================================================= Applied Auxiliary Computations Time Factors Corresponding to Full Astronomical JD T = 0.250867039318 Julian centuries reckoned from J2000.0 t = 0.025086703931 Julian millennia reckoned from J2000.0 Nutations (IAU 2000B Series) +1.518" = +0.0004217101° = Nutation in ecliptical longitude +9.196" = +0.0025544207° = Nutation in ecliptical obliquity +0.093s = +0.0003869135° = Equation of the equinoxes Mean Obliquity of the Ecliptic 23° 26' 09.705" = 23.4360291976° True Obliquity of the Ecliptic 23° 26' 18.901" = 23.4385836183°
Jay Tanner - PHP Science Labs - 2025 - 1.7