As long as you have ULX, ULIB and UTime installed, you're a superadmin and you have setup some groups,

Open up your xgui (!xgui or !menu), head over to the settings tab and click the apromote tab,

select your settings on the left checkboxes.

you will notice your groups in a list followed by a number, that number is how many hours before the player in that group will be promoted to the next rank

You should leave your admin ranks and any ranks you dont want people to automaticly get promoted to at : -1 this means that those groups are excluded from promotions.

Lets say you have people starting at a "guest" rank and you want the player to be promoted to the "player" rank after 1 hour. You would put a 1 on the "player" ranks time.

Then lets say you want them to be promoted to a "member" rank after 5 hours of played time, you would put a 5 on the "member" rank and so on and so forth.

Remember to hit Apply after every change to save it!