Is a colon placed between the hours and minutes? ARRL Op Manual 9th ed p 1-32 indicates no But a lot of printed and online forms have the colon. Optional? Also, is the letter z necessary after the time? I don't see that in the Op Manual, but ISO-8601 indicates the use of it. Sort of. Or is Ham world all it's own slippery convention? Just curios so I can look like I know what I'm doing. Brian N7BKV
There is no "proper" way to write UTC time or any other time zone. It depends on who or what the written record is intended for. Time zone and printed time format are not really related. Some formats include the time zone or offset, some don't depending on the understanding between writer and reader. I think in ISO-8601 always includes offset from UTC but "z" is an abbreviation for "+00:00"
Brian, I’ve seen UTC written both ways, with the colon and without. Both are correct. The colon is simply a separator between hours and minutes. If you feel more comfortable using it, use it; if not, not. “Z” is just another abbreviation for GMT / UTC. If memory serves, it comes from the military one letter designation of the major time zones of the world. “Z” is simply another designation.
Generally, and also in military, aviation and maritime usage, NO Colon is used; e.g. 0147. The world is divided into time zones which in civilian usage have names, e.g. Eastern Time Zone. However, they also have letter designators which are used particularly in military communications. UTC is also the "Z" time zone. Eastern Time Zone is "R". Ex. 0147Z, spoken "Zero One Forty Seven Zulu'; 2314R spoken "Twenty Three Fourteen Romeo". Also in ordinary conversation, time may be referred to as "Local", e.g. spoken "1925 Local". -Amateurs rarely use time referenced to letter zones other than "Z". Usage that grates on a sailor: The Army and USAF will speak of "0830 Hours". The USN/USMC, maritime and aviation simply say either "0830", "0830 Local" or "0830 Romeo/Zulu, etc". There are no "hours". shrug -How about 1:15pm "One Fifteen p.m. Hours"?. Time zone name Letter UTC offset Alpha Time Zone A UTC+01:00 Bravo Time Zone B UTC+02:00 Charlie Time Zone C UTC+03:00 Charlie Star Time Zone C* UTC+03:30 Delta Time Zone D UTC+04:00 Delta Star Time Zone D* UTC+04:30 Echo Time Zone E UTC+05:00 Echo Star Time Zone E* UTC+05:30 Foxtrot Time Zone F UTC+06:00 Foxtrot Star Time Zone F* UTC+06:30 Golf Time Zone G UTC+07:00 Hotel Time Zone H UTC+08:00 India Time Zone I UTC+09:00 Kilo Time Zone K UTC+10:00 Lima Time Zone L UTC+11:00 Mike Time Zone M UTC+12:00 November Time Zone N UTC−01:00 Oscar Time Zone O UTC−02:00 Papa Time Zone P UTC−03:00 Quebec Time Zone Q UTC−04:00 Romeo Time Zone R UTC−05:00 Sierra Time Zone S UTC−06:00 Tango Time Zone T UTC−07:00 Uniform Time Zone U UTC−08:00 Victor Time Zone V UTC−09:00 Whiskey Time Zone W UTC−10:00 X-ray Time Zone X UTC−11:00 Yankee Time Zone Y UTC−12:00 Zulu Time Zone Z UTC±00:00
Thanks. I want to get the ham stuff sorted out from my former military habits. Want to sound like friend, not a field commander on the air.
How do they deal with daylight saving? If I'm on the US east coast and it's 8am in summer, would I say it's 0800Q or 0700R ?
I think they ignore it since thee are some local places that don't use it. If you use the UTC letters stay standard (0700R), or least confusing straight, UTC. OP, generally don't use the Z. As to the colon, write it anyway you want. It looks like ADIF does not use it, but some applications do. EQSL wants it, looks like QRZ does too.
They don't. Time zones are always the same offset. Any daylight savings or other adjustment would simply be "Local" time.