4-2-12 Time

a. 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

b. To convert from 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.

c. 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

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

e. 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