final Calendar calendar = Calendar.getInstance();
final int hour = calendar.get(Calendar.HOUR);
if(hour >= 12 && hour <= 15)
qiveQuestToPlayer(player);Code: Java
Или так с явкой 8
final ZonedDateTime dateTime = ZonedDateTime.now();
final int hour = dateTime.getHour();
if(hour >= 12 && hour <= 15)
qiveQuestToPlayer(player);Code: Java