Facebook的文档解释timezone字段是用户相对于UTC的时区偏移量.

Facebook's documentation explains that the timezone field is the user's timezone offset from UTC.

目前尚不清楚，但是我通过实验发现，它不一定是用户的 current 偏移量，而是用户上次登录时的偏移量.如果用户更改时区，或者夏令时开始或结束，则直到用户下一次登录时，这才会反映在Facebook数据中.

What it doesn't make clear, but I have found through experimentation, is that it is not necessarily the user's current offset, but it instead it is the offset as of the user's last log in. If the user changes time zones, or daylight saving time begins or ends, that will not be reflected in the Facebook data until the user's next log in.

另请参见此相关问题.