[Dignity]

pawn Код:

// Outside any callback
new bool: NewbieChatCooldown[MAX_PLAYERS];

// Top of your command or wherever, anywhere but before the actual code
if(NewbieChatCooldown[playerid]) return SendClientMessage(playerid, -1, "You can't talk in newbie chat yet!");

// After they have sent a message, do this:
NewbieChatCooldown[playerid] = true;
SetTimerEx("NewbieChatCDExpire", 30000, false, "i", playerid);

// Anywhere outside of a callback
forward NewbieChatCDExpire(playerid);
public NewbieChatCDExpire(playerid);
{
    NewbieChatCooldown[playerid] = false;

    return true;
}

EDIT: Make sure to NOT place the timer inside of the loop.