This is where this date&time retrieval mechanism sort of breaks: 1) Timezone of server is set to one other than the geographical location's 2) Gzip-compressed

This is where this date&time retrieval mechanism sort of breaks: 1) Timezone of server is set to one other than the geographical location's 2) Gzip-compressed page or asset is cached. Therefore the embedded date/time is from an unknown past. So this reduces the good guesses a bit.