6a9a4f34bd
Export them in UTC, not the local timezone. This way the output is the same everywhere. The timezone information stored in the file is still ignored, since there seems to be no simple way to export it correctly. Format them according to ISO 8601, which we generally use for exporting dates. Fixes fate-flv-demux, which was broken since 958bea5248f87116b0dd080461aa70c14ea86cf0 on some platforms.