[Misiur]

This is a little bit more complex, but not too much. You need to store the time remaining, so:

pawn Код:

//change
if(g_var[playerid] == 1)
//to
if(PlayerInfo[playerid][pCountDown])

//change
if(g_var[playerid] == 0 //(... rest of the line)
//to
if(!PlayerInfo[playerid][pCountDown] //(...)

//change
SetTimerEx("CountDown",1200*1000, false, "d", playerid); 
//to
PlayerInfo[playerid][pCountDown] = 20 * 60; //time stored in seconds
SetTimerEx("CountDown", 1000, false, "d", playerid);

//change
public CountDown(playerid) 
{ 
    g_var[playerid] = 0; 
} 
//to
public CountDown(playerid) 
{
    if(PlayerInfo[playerid][pCountDown]-- > 0) {
        SetTimerEx("CountDown", 1000, false, "d", playerid); 
    }
}

//In OnPlayerLogin or similar
if(PlayerInfo[playerid][pCountDown]) {
    SetTimerEx("CountDown", 1000, false, "d", playerid); 
}