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
2461045.5
0.190289351852
-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 05 [Monday] Gregorian JD Number = 2461046 JD00 = 2461045.5 = JD for 00h of date Local Time = 04:34:01 = 0.190289351852 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) = 2461045.898622685185 Longitude = -76° 49' 23.915" = -76.8233097222° (W) = -05h 07m 17.594s = -5.1215539815 h ================================================================= Local Mean Sidereal Time at Longitude -76.8233097222° (W) 11h 26m 42.530s = 11.4451470919 h 171° 40' 37.94" = 171.6772063780° Local True Sidereal Time at Longitude = -76.8233097222° (W) 11h 26m 42.912s = 11.4452533529 h 171° 40' 43.68" = 171.6788002936° Greenwich Mean Sidereal Time 16h 34m 00.124s = 16.5667010734 h 248° 30' 01.858" = 248.5005161003° Greenwich True Sidereal Time 16h 34m 00.506s = 16.5668073344 h 248° 30' 07.596" = 248.5021100160° ================================================================= Applied Auxiliary Computations Time Factors Corresponding to Full Astronomical JD T = 0.260120427725 Julian centuries reckoned from J2000.0 t = 0.026012042772 Julian millennia reckoned from J2000.0 Nutations (IAU 2000B Series) +6.254" = +0.0017372571° = Nutation in ecliptical longitude +8.174" = +0.0022704611° = Nutation in ecliptical obliquity +0.383s = +0.0015939156° = Equation of the equinoxes Mean Obliquity of the Ecliptic 23° 26' 09.272" = 23.4359088804° True Obliquity of the Ecliptic 23° 26' 17.446" = 23.4381793415°
Jay Tanner - PHP Science Labs - 2026 - 1.7