AIM 4-2-12

FAA uses Coordinated Universal Time (UTC) for all operations. The word “local” or the time zone equivalent must be used to denote local when local time is given during radio and telephone communications. The term “Zulu” may be used to denote UTC. EXAMPLE-

0920 UTC zero niner two zero,

zero one two zero pacific or local,

or one twenty AM

To convert from Standard Time to Coordinated Universal Time: TBL 4-2-12 Standard Time to Coordinated Universal Time Eastern Standard Time Central Standard Time

Mountain Standard Time

Pacific Standard Time

Alaska Standard Time

Hawaii Standard Time

Add 5 hours

Add 6 hours

Add 7 hours

Add 8 hours

Add 9 hours

Add 10 hours

NOTE-

For daylight time, subtract 1 hour.

A reference may be made to local daylight or standard time utilizing the 24-hour clock system. The hour is indicated by the first two figures and the minutes by the last two figures. EXAMPLE-

0000 zero zero zero zero

0920 zero niner two zero

Time may be stated in minutes only (two figures) in radiotelephone communications when no misunderstanding is likely to occur.

Current time in use at a station is stated in the nearest quarter minute in order that pilots may use this information for time checks. Fractions of a quarter minute less than 8 seconds are stated as the preceding quarter minute; fractions of a quarter minute of 8 seconds or more are stated as the succeeding quarter minute. EXAMPLE-

0929:05 time, zero niner two niner

0929:10 time, zero niner two niner and one-quarter