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
2460738.5
0.333414351852
-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 Mar 04 [Tuesday] Gregorian JD Number = 2460739 JD00 = 2460738.5 = JD for 00h of date Local Time = 08:00:07 = 0.333414351852 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) = 2460739.041747685185 Longitude = -76° 49' 23.915" = -76.8233097222° (W) = -05h 07m 17.594s = -5.1215539815 h ================================================================= Local Mean Sidereal Time at Longitude -76.8233097222° (W) 18h 42m 59.888s = 18.7166356012 h 280° 44' 58.32" = 280.7495340179° Local True Sidereal Time at Longitude = -76.8233097222° (W) 18h 42m 59.957s = 18.7166547081 h 280° 44' 59.35" = 280.7498206210° Greenwich Mean Sidereal Time 23h 50m 17.482s = 23.8381895827 h 357° 34' 22.237" = 357.5728437402° Greenwich True Sidereal Time 23h 50m 17.551s = 23.8382086896 h 357° 34' 23.269" = 357.5731303433° ================================================================= Applied Auxiliary Computations Time Factors Corresponding to Full Astronomical JD T = 0.251719144358 Julian centuries reckoned from J2000.0 t = 0.025171914435 Julian millennia reckoned from J2000.0 Nutations (IAU 2000B Series) +1.125" = +0.0003123786° = Nutation in ecliptical longitude +9.597" = +0.0026658819° = Nutation in ecliptical obliquity +0.069s = +0.0002866031° = Equation of the equinoxes Mean Obliquity of the Ecliptic 23° 26' 09.665" = 23.4360181181° True Obliquity of the Ecliptic 23° 26' 19.262" = 23.4386840000°
Jay Tanner - PHP Science Labs - 2025 - 1.7