使用PHP和MySQL处理时间戳（我的理论是否正确？）

I've been researching timestamps in PHP & MySQL. My undertanding is that UNIX timestamps only exist in GMT ... the whole point being that you convert it into the users timezone (GMT +/- timezone = users localtime). I'm doing this successfuly by saving the timestamp in it's "raw" form (as a 10 digit long int) and converting it into localtime in the query I've been researching timestamps in PHP & MySQL