Java Utililty Methods Hour

Calendar cal = Calendar.getInstance();
cal.setTimeInMillis(createAt);
return cal.get(Calendar.HOUR);

return nextHour().getTime() - System.currentTimeMillis();

return calendar.get(Calendar.HOUR_OF_DAY);

Calendar nextQuarter = Calendar.getInstance();
nextQuarter.set(Calendar.SECOND, 1);
nextQuarter.set(Calendar.MILLISECOND, 0);
int minute = nextQuarter.get(Calendar.MINUTE);
nextQuarter.add(Calendar.MINUTE, 15 - (minute % 15));
long alarmOnQuarterHour = nextQuarter.getTimeInMillis();
long now = System.currentTimeMillis();
long delta = alarmOnQuarterHour - now;
...

return getAnHourBack(new Date());

Calendar cal = Calendar.getInstance();
cal.setTime(new Date());
return String.valueOf(cal.get(Calendar.HOUR_OF_DAY) == 0 ? 23 : cal.get(Calendar.HOUR_OF_DAY) - 1);

Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
cal.add(Calendar.HOUR, hours);
return cal;

Calendar calendar;
calendar = new GregorianCalendar();
String hour = Integer.toString(calendar.get(Calendar.HOUR_OF_DAY));
return hour;

Calendar cal = Calendar.getInstance();
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
return cal.getTime();

Calendar cal = Calendar.getInstance();
return cal.get(Calendar.HOUR_OF_DAY) + cal.get(Calendar.MINUTE) / 60f;