// Top
forward PayDay( ); // Forwarding the function

// OnGameModeInit
SetTimer( "PayDay", 1800000, true ); // Setting the timer to call every 30 minutes (1.8 million milliseconds)

// Outside callbacks
public PayDay( )
{
    for( new i; i < MAX_PLAYERS; i++ ) // Can be substituted with foreach (Recommended)
    {
        if( IsPlayerConnected( i ) // Is the player connected?
        {
            GivePlayerMoney( i, 5000 ); // Give the player some money
        }
    }
}

// Top of script

new
    CurrentSession[ MAX_PLAYERS ] // Create an array which keeps track of how many seconds the player has been on the server.
;

forward PayDay( ); // Forwarding the payday function.
forward ThreeSecondTimer( ); // Forwarding the session increment function.

// OnGameModeInit

SetTimer( "PayDay", 1800000, true ); // Setting the payday timer for 30 minutes.
SetTimer( "ThreeSecondTimer", 3000, true ); // Setting the session timer for 3 seconds.

// OnPlayerConnect

CurrentSession[ playerid ] = 0; // When a new player connects, their session time should be 0.

// Outside callbacks

public ThreeSecondTimer( )
{
    for( new i; i < MAX_PLAYERS; i++ ) // Can be substituted with foreach (Recommended)
    {
        if( IsPlayerConnected( i ) ) // If the player is connected
        {
            CurrentSession[ i ] += 3; // Add 3 to their seconds connected.
        }
    }
    return 1;
}

public PayDay( )
{
    for( new i; i < MAX_PLAYERS; i++ ) // Can be substituted with foreach (Recommended)
    {
        if( IsPlayerConnected( i ) ) // If the player is connected
        {
            if( CurrentSession[ i ] >= 900 ) // If the player has been connected for at least 15 minutes.
            {
                GivePlayerMoney( i, 5000 ); // Give the player money
            }
            else
            {
                SendClientMessage( i, 0xFFFFFFFF, "Server: You haven't played long enough!" ); // The player has not been connected for at least 15 minutes.
            }
            
            CurrentSession[ i ] = 0; // Reset the session.
        }
    }
    return 1;
}

SetTimerEx("payday", time, true, "d", playerid);//time has to be defined

public payday(playerid)
     {
      GameTextForPlayer(playerid, "PAYDAY!!!", 10000, 3);
      SendClientMessage(playerid, YOUR_COLOR_HERE, "YOUR MESSAGE");
      GivePlayerMoney(playerid, 5000);// or whatever you want
      return 1;
     }