Paul Eggert said:
| Unfortunately tm_gmtoff is not standardized by C or POSIX, perhaps | because standardizers mistakenly thought that strftime %z was enough.
No, it would have been because tm_gmtoff isn't available everywhere (and most particularly, wasn't available on the main reference system from which most of POSIX was copied.) strftime %z wasn't available on the main reference system either, nor was it universally supported, and yet it was added to the C standard.
I was involved in the C99 standardization work. We knew that there were lots of issues in this area and asked time experts (from memory, including people on this list) for proposals. Nothing arrived in the relevant timescales. I stopped being involved a few years later, so don't know what has happened since. But the WG14 I was involved in would welcome a proposal that would sort things out once and for all based on current knowledge. -- Clive D.W. Feather | If you lie to the compiler, Email: clive@davros.org | it will get its revenge. Web: http://www.davros.org | - Henry Spencer Mobile: +44 7973 377646