How to create a Java Date object of midnight today and midnight tomorrow?
date, java
Solution
java.util.Calendar
// today
Calendar date = new GregorianCalendar();
// reset hour, minutes, seconds and millis
date.set(Calendar.HOUR_OF_DAY, 0);
date.set(Calendar.MINUTE, 0);
date.set(Calendar.SECOND, 0);
date.set(Calendar.MILLISECOND, 0);
// next day
date.add(Calendar.DAY_OF_MONTH, 1);
JDK 8 - java.time.LocalTime and java.time.LocalDate
LocalTime midnight = LocalTime.MIDNIGHT;
LocalDate today = LocalDate.now(ZoneId.of("Europe/Berlin"));
LocalDateTime todayMidnight = LocalDateTime.of(today, midnight);
LocalDateTime tomorrowMidnight = todayMidnight.plusDays(1);
Joda-Time
If you're using a JDK < 8, I recommend Joda Time, because the API is really nice:
DateTime date = new DateTime().toDateMidnight().toDateTime();
DateTime tomorrow = date.plusDays(1);
Since version 2.3 of Joda Time `DateMidnight` is deprecated, so use this:
DateTime today = new DateTime().withTimeAtStartOfDay();
DateTime tomorrow = today.plusDays(1).withTimeAtStartOfDay();
Pass a time zone if you don't want the JVM’s current default time zone.
DateTimeZone timeZone = DateTimeZone.forID("America/Montreal");
DateTime today = new DateTime(timeZone).withTimeAtStartOfDay(); // Pass time zone to constructor.
Problem
In my code I need to find all my things that happened today. So I need to compare against dates from today at 00:00 AM (midnight early this morning) to 12:00 PM (midnight tonight). I know ... ``` Date today = new Date(); ``` ... gets me right now. And ... ``` Date beginning = new Date(0); ``` ... gets me zero time on Jan 1, 1970. But what's an easy way to get zero time today and zero time tomorrow? UPDATE I did this, but surely there's an easier way? ``` Calendar calStart = new GregorianCalendar(); calStart.setTime(new Date()); calStart.set(Calendar.HOUR_OF_DAY, 0); calStart.set(Calendar.MINUTE, 0); calStart.set(Calendar.SECOND, 0); calStart.set(Calendar.MILLISECOND, 0); Date midnightYesterday = calStart.getTime(); Calendar calEnd = new GregorianCalendar(); calEnd.setTime(new Date()); calEnd.set(Calendar.DAY_OF_YEAR, calEnd.get(Calendar.DAY_OF_YEAR)+1); calEnd.set(Calendar.HOUR_OF_DAY, 0); calEnd.set(Calendar.MINUTE, 0); calEnd.set(Calendar.SECOND, 0); calEnd.set(Calendar.MILLISECOND, 0); Date midnightTonight = calEnd.getTime(); ```