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
2461064.5
0.084050925926
-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 = 2026 Jan 24 [Saturday] Gregorian JD Number = 2461065 JD00 = 2461064.5 = JD for 00h of date Local Time = 02:01:02 = 0.084050925926 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) = 2461064.792384259259 Longitude = -76° 49' 23.915" = -76.8233097222° (W) = -05h 07m 17.594s = -5.1215539815 h ================================================================= Local Mean Sidereal Time at Longitude -76.8233097222° (W) 10h 08m 12.950s = 10.1369306375 h 152° 03' 14.25" = 152.0539595624° Local True Sidereal Time at Longitude = -76.8233097222° (W) 10h 08m 13.356s = 10.1370431997 h 152° 03' 20.33" = 152.0556479962° Greenwich Mean Sidereal Time 15h 15m 30.545s = 15.2584846190 h 228° 52' 38.169" = 228.8772692848° Greenwich True Sidereal Time 15h 15m 30.950s = 15.2585971812 h 228° 52' 44.248" = 228.8789577185° ================================================================= Applied Auxiliary Computations Time Factors Corresponding to Full Astronomical JD T = 0.260637710725 Julian centuries reckoned from J2000.0 t = 0.026063771072 Julian millennia reckoned from J2000.0 Nutations (IAU 2000B Series) +6.625" = +0.0018402765° = Nutation in ecliptical longitude +8.537" = +0.0023713047° = Nutation in ecliptical obliquity +0.405s = +0.0016884337° = Equation of the equinoxes Mean Obliquity of the Ecliptic 23° 26' 09.248" = 23.4359021545° True Obliquity of the Ecliptic 23° 26' 17.784" = 23.4382734592°
Jay Tanner - PHP Science Labs - 2026 - 1.7