You are here: Home USNO Astronomical Applications Data Services Celestial Navigation Data for Assumed Position and Time
The USNO websites aa.usno.navy.mil, ad.usno.navy.mil, aristarchus.usno.navy.mil, maia.usno.navy.mil, rorf.usno.navy.mil, toshi.usno.navy.mil, and tycho.usno.navy.mil are undergoing modernization efforts. The expected completion of the work and the estimated return of service is Fall 2020, subject to change due to potential impacts of COVID-19.
 

Celestial Navigation Data for Assumed Position and Time

Our data services have moved here. Please update your bookmarks.

USNO Master Clock Time
Javascript must be Enabled