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
2460892.5
0.367187500000
-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 Aug 05 [Tuesday] Gregorian JD Number = 2460893 JD00 = 2460892.5 = JD for 00h of date Local Time = 08:48:45 = 0.367187500000 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) = 2460893.075520833333 Longitude = -76° 49' 23.915" = -76.8233097222° (W) = -05h 07m 17.594s = -5.1215539815 h ================================================================= Local Mean Sidereal Time at Longitude -76.8233097222° (W) 05h 38m 55.404s = 5.6487234072 h 84° 43' 51.06" = 84.7308511073° Local True Sidereal Time at Longitude = -76.8233097222° (W) 05h 38m 55.653s = 5.6487924874 h 84° 43' 54.79" = 84.7318873104° Greenwich Mean Sidereal Time 10h 46m 12.999s = 10.7702773886 h 161° 33' 14.979" = 161.5541608296° Greenwich True Sidereal Time 10h 46m 13.247s = 10.7703464689 h 161° 33' 18.709" = 161.5551970328° ================================================================= Applied Auxiliary Computations Time Factors Corresponding to Full Astronomical JD T = 0.255936359228 Julian centuries reckoned from J2000.0 t = 0.025593635922 Julian millennia reckoned from J2000.0 Nutations (IAU 2000B Series) +4.066" = +0.0011293913° = Nutation in ecliptical longitude +8.835" = +0.0024540941° = Nutation in ecliptical obliquity +0.249s = +0.0010362032° = Equation of the equinoxes Mean Obliquity of the Ecliptic 23° 26' 09.468" = 23.4359632838° True Obliquity of the Ecliptic 23° 26' 18.303" = 23.4384173779°
Jay Tanner - PHP Science Labs - 2025 - 1.7