Zulu Time Converter
Convert Zulu time (UTC) to any local time zone and back, with daylight saving handled.
Why “Zulu”
Time zones get letters in the military and aviation alphabet, and UTC — the
zero-offset zone — is Z. Spelled out in the NATO alphabet that is
“Zulu”, so 1345Z is read “thirteen forty-five
Zulu”.
The point of using it is that everyone shares one clock. Flight plans, weather observations, satellite passes and incident logs are all timestamped in Zulu so that a message crossing several zones cannot be misread.
Zulu, UTC and GMT
For everyday purposes Zulu and UTC are the same thing. GMT is a time zone that happens to sit at UTC+0 in winter — but the UK shifts to UTC+1 in summer, so British local time is not Zulu for half the year. That is a common source of error, and why this calculator asks for a date.
Daylight saving
UTC never changes. Local zones do, on dates that differ by country and occasionally by year. The conversion above uses the actual rules in force on the date you enter rather than a fixed offset, so a meeting scheduled across a clock-change weekend comes out right.