IERS Rapid Service / Prediction Center

U.S. Naval Observatory

IERS Bulletins

IERS Bulletin B ("Final" Earth Orientation Paramter Values)

• IERS Bulletin B reports the "final" determinations for polar motion, UT1-UTC, and nutation offsets at five-day intervals. Smoothed one-day values are also provided. IERS Bulletin B is prepared by the IERS Earth Orientation Center based at the Paris Observatory and is updated monthly.
• Locally hosted Bulletin B
• Archived issues of Bulletin B
• Explanatory supplement to IERS Bulletins A and B
• Interpolating IERS Earth orientation data (IERS Gazette #13)

IERS Bulletin C (Leap Second Announcement)

• Information about leap second announcements
• Table of leap seconds since 1961; differences between International Atomic Time (TAI) and Coordinated Universal Time (UTC)

IERS Bulletin D (Announcements of DUT1)

• Values of DUT1 = (UT1-UTC) transmitted with time signals are published in IERS Bulletin D to a precision of 0.1 s
• Archived issues of Bulletin D