[AmirRFCNR]

Under OnPlayerSpawn

pawn Code:

if(JailTimer[playerid] > 0) //do your jail timer here if > 0
    {
     PInfo[playerid][pJail] = 1; //send player to jail
    }

that if you already save jail timer when player quit

else

pawn Code:

if(PInfo[playerid][pJail] == 1)
{
   SetPlayerPos(playerid, -1346.5848,1323.8483,2.4516); //set player post in LS jail
   JailTimer[playerid] = SetTimerEx("Unjail",second*1000, false, "i", playerid); //start the timer to unjail
}

Don't forget to save if player jailed in OnPlayerDisconnect