Solved -

Fixed.

 

PlayFriik here is my example countdown:

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Code:java

 
 
import org.bukkit.Bukkit;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerJoinEvent;
import org.bukkit.plugin.PluginManager;
import org.bukkit.plugin.java.JavaPlugin;
 
public class Main extends JavaPlugin implements Listener{
 
    int task;
    int time = 30;
 
    public void onEnable(){
 
        PluginManager pm = Bukkit.getServer().getPluginManager();
        pm.registerEvents(this, this);
 
    }
 
 
    public void onDisable(){
 
    }
 
    @EventHandler
    public void onPlayerJoin(PlayerJoinEvent e){
        Player p = e.getPlayer();
 
    task = Bukkit.getScheduler().scheduleSyncRepeatingTask(this, new Runnable() {
        public void run() {
        time--; //You want to subtract time by 1 each time this is ran ! not on else statement or anywhere else.
        if(time == 0) {
        Bukkit.getScheduler().cancelTask(task);
        } else if (time == 20) {
            System.out.println("20");
        }else if (time == 15){
            System.out.println("15");
        }else if (time == 10){
            System.out.println("10");
        }else if (time < 10){
            System.out.println(time); //couting down from 10 to 0
                }
            }
        }, 0, 20);
    }
}
 

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I tried, but I just can't figure out how to do that.. :/
Also this scoreboard has option "scoreboard.add("SomeTextHere", ScoreHere)", but I have no idea, how to remove 1 from it..?