If this actually worked, M.’s views on marshmallows would have been at the top of the page; Facebook doesn’t have a clue what I want to read. I’ve always preferred the chronological order. I think I like the new “more of this person, less of that person” settings though.
Since MySQL 5 I believe, the TIMESTAMP data type is converted to UTC when it's stored and converted back into the timezone of the server or connection set timezone when retrieved. Storing the date and time as a TIMESTAMP allows you to perform date operations in the query, such as adding or subtracting time from it for a WHERE clause.
However, make sure you use TIMESTAMP and not DATETIME for this. DATETIME does not handle the timezone conversion.