NOTICE ADVISORY TO NAVSTAR USERS (NANU) #062-97182
SUBJ: LEAP SECOND
1. CONDITION: THE INTERNATIONAL EARTH ROTATION SERVICE (IERS) HAS
ANNOUNCED THE INTRODUCTION OF A LEAP SECOND TO OCCUR AT THE END OF
JUNE 1997.
2. COORDINATED UNIVERSAL TIME (UTC) WILL SEQUENCE AS FOLLOWS:
             30 JUNE 1997  23 HOURS 59 MINUTES 59 SECONDS
             30 JUNE 1997  23 HOURS 59 MINUTES 60 SECONDS
              1 JULY 1997  0 HOURS 0 MINUTES 0 SECONDS
3. FOR GPS, AS WITH PREVIOUS LEAP SECOND UPDATES, THE UTC DATA IN SUBFRAME 4,
PAGE 18 OF THE NAVIGATION MESSAGE WILL CHANGE IN ACCORDANCE WITH ICD-GPS-200.
    BEFORE THE LEAP SECOND
    GPS-UTC IS 11 (GPS IS AHEAD OF UTC BY 11 SECONDS)
    AFTER THE LEAP SECOND
    GPS-UTC WILL BE 12 (GPS WILL BE AHEAD OF UTC BY 12 SECONDS)
4. POC: NAVIGATION ANALYST AT COMMERCIAL (719) 567-6378 OR DSN
560-6378.