Terrestrial Time (TT) Calculator
Calculate Terrestrial Time (TT), the modern astronomical time standard used for geocentric ephemerides. TT = TAI + 32.184 seconds.
Time Scales
UTC
Tue, 07 Apr 2026 15:18:51 GMT
2026-04-07T15:18:51.000Z
TAI
Tue, 07 Apr 2026 15:19:28 TAI
2026-04-07T15:19:28.000 TAI
TT (Terrestrial Time)
Tue, 07 Apr 2026 15:20:00 TT
2026-04-07T15:20:00.184 TT
TDB (Barycentric Dynamical)
Tue, 07 Apr 2026 15:20:00 TDB
2026-04-07T15:20:00.185 TDB
Offsets and Julian Dates
TT - UTC
69.184s
TT - TAI
32.184s
TAI - UTC
37s
TDB - TT
1.653ms
JD (TT)
2461138.138891
Julian Century (T)
0.262645829
Seconds since J2000.0
828847200.184s
About Terrestrial Time
Terrestrial Time (TT) is the modern astronomical time standard for geocentric ephemerides. It was introduced in 1991 to replace Terrestrial Dynamical Time (TDT). TT is defined as TAI + 32.184 seconds, where 32.184 seconds is the offset to maintain continuity with the older Ephemeris Time (ET).