[tzahola]

There is an unambiguous way to represent time zones:

UTC±hh:mm

[BerislavLopac]

To be pedantic, that's the unambiguous way to represent the UTC offset, not timezones. Different timezones can have the same offset at some moments, but not at others.

[tzahola]

GGP probably meant including the UTC offsets in the timestamps, not timezone names like "Europe/Berlin" or whatever.

[icebraining]

Right, but the time zone might not have the same offset in the future, they're not interchangeable.