Either a new transformer (DateTimeSorter) or an extra option in the regular Sorter to sort on date/time attributes as depending on the notation the alphabetic/numeric options don't always give the right results.
Open
Date/time sorting
The Sorter ought to work if your timestamps are in internal FME format, no? I.e. YYYYMMDD or YYMMDDHHMMSS. Or is there a bug that I don't know of?
If the Sorter needs to work with an arbitrary date format, I suspect it will be (a lot) slower.