UT1 Time Calculator
Calculate UT1 (Universal Time) based on Earth's rotation. UT1 is derived from astronomical observations and differs from UTC by up to 0.9 seconds.
Results
UTC
Tue, 07 Apr 2026 15:18:52 GMT
UT1
Tue, 07 Apr 2026 15:18:52 UT1
DUT1
0.0000s
Julian Date
2461138.138102
MJD
61137.638102
Julian Century
0.262645807
Earth Rotation Parameters
Greenwich Mean Sidereal Time (GMST)
04:22:30.87
65.628616 degrees
Earth Rotation Angle (ERA)
65.292080 degrees
1.139562 radians
About UT1
UT1 (Universal Time 1) is a time scale based on the rotation of the Earth. Unlike UTC (which is based on atomic clocks), UT1 is determined by observations of distant celestial objects. The difference between UT1 and UTC is called DUT1.
DUT1 = UT1 - UTC, and is kept within +/- 0.9 seconds by adding leap seconds to UTC. The International Earth Rotation and Reference Systems Service (IERS) publishes DUT1 values regularly.