[mansonh]

Search for a dini tutorial or read the samp basics of it
https://sampwiki.blast.hk/wiki/Useful_Fu....28Dini.inc.29

Then have a variable for player play time.
new playerplaytime[MAX_PLAYERS];

When someone joins your server load their info from dini.
And ever say minute or so update a players playtime.
https://sampwiki.blast.hk/wiki/SetTimerEx
https://sampwiki.blast.hk/wiki/Gettime or https://sampwiki.blast.hk/wiki/Tickcount