public static String generateId(@NotNull Calendar calendar, char OSChar) {
    int year = calendar.get(Calendar.YEAR);
    if (year < 2000) year = 2000;
    if (year > 2099) year = 2099;
    calendar.set(Calendar.YEAR, year);
    return new SimpleDateFormat("ddMMyy", Locale.ENGLISH).format(calendar.getTime()) + OSChar + UUID.randomUUID();
  }
public static String generateId(@NotNull Calendar calendar, char OSChar)