You are here: Home USNO Earth Orientation EO Information Center General Information Bulletin D
The USNO websites,,,,, and are undergoing modernization efforts. The expected completion of the work and return of service is estimated as 30 April 2020. Please submit a requirements form to the USNOPAO if the information you are seeking is not accessible via other means.

Bulletin D

IERS Bulletin D announces UT1-UTC values.

  • values of DUT1 = (UT1-UTC) transmitted with time signals are published in IERS Bulletin D to a precision of 0.1 s
  • previous issues of Bulletin D are archived here
USNO Master Clock Time
Javascript must be Enabled