Question

For time.timezone, the Python documentation says:

The offset of the local (non-DST) timezone, in seconds west of UTC (negative in most of Western Europe, positive in the US, zero in the UK).

Does anybody know why it returns a negative value for most of Western Europe? These countries are in a positive offset, and not in a negative one.

Example: Brussels is in UTC+1 timezone…

Answer 1

This is a Unix artefact. Although the standard numeric description for timezones is in hours and minutes east from UTC (UTC+1 for Brussels, UTC-5 for New York, etc.) the Unix timezone is measured in seconds west from UTC.

From http://pubs.opengroup.org/onlinepubs/7908799/xsh/tzset.html:

The external variable timezone is set to the difference, in seconds, between Coordinated Universal Time (UTC) and local standard time, for example:

TZ  timezone
EST 5*60*60
GMT 0*60*60
JST -9*60*60
MET -1*60*60
MST 7*60*60
PST 8*60*60

As to why Unix has it backwards, I’d guess it’s a historical accident, probably because Unix was originally developed in the USA.