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
2461004.5
0.413506944444
-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 Nov 25 [Tuesday] Gregorian JD Number = 2461005 JD00 = 2461004.5 = JD for 00h of date Local Time = 09:55:27 = 0.413506944444 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) = 2461005.121840277777 Longitude = -76° 49' 23.915" = -76.8233097222° (W) = -05h 07m 17.594s = -5.1215539815 h ================================================================= Local Mean Sidereal Time at Longitude -76.8233097222° (W) 14h 07m 22.563s = 14.1229340863 h 211° 50' 38.44" = 211.8440112942° Local True Sidereal Time at Longitude = -76.8233097222° (W) 14h 07m 22.784s = 14.1229954924 h 211° 50' 41.76" = 211.8449323858° Greenwich Mean Sidereal Time 19h 14m 40.157s = 19.2444880678 h 288° 40' 02.356" = 288.6673210165° Greenwich True Sidereal Time 19h 14m 40.378s = 19.2445494739 h 288° 40' 05.672" = 288.6682421082° ================================================================= Applied Auxiliary Computations Time Factors Corresponding to Full Astronomical JD T = 0.259004020267 Julian centuries reckoned from J2000.0 t = 0.025900402026 Julian millennia reckoned from J2000.0 Nutations (IAU 2000B Series) +3.614" = +0.0010039263° = Nutation in ecliptical longitude +8.396" = +0.0023323543° = Nutation in ecliptical obliquity +0.221s = +0.0009210916° = Equation of the equinoxes Mean Obliquity of the Ecliptic 23° 26' 09.324" = 23.4359233965° True Obliquity of the Ecliptic 23° 26' 17.721" = 23.4382557508°
Jay Tanner - PHP Science Labs - 2025 - 1.7