import java.text.*;

static S localTime_24_minutesToZero(long time) {
  SimpleDateFormat sdf = new SimpleDateFormat("HH");
  sdf.setTimeZone(localTimeZone());
  ret sdf.format(time) + ":00";
}

static S localTime_24_minutesToZero() {
  ret localTime_24_minutesToZero(now());
}