What I've never been quite sure of when significant distances from the UK, is whether the DATE is local or as at Greenwich?
Always Greenwich date if that's the time you're logging.
Example:
Flight, in Sydney, in January. (Aust EST = GMT + 11)
T/o @ 0600L on January 1st.
Logged as
T/o 1900Z on December 31st.
If you logged that as 1900Z January 1st, it hadn't happened yet
