convert Date to a quarter of an hour type JAVA

Question

I am looking for a way to convert the datatype DATE [JAVA]

to a quarter of an hour format, so that

2010-08-15 12:05:15 will be 2010-08-15 12:00:00

Are there any ready to go methods in JAVA already?

How would you do this?

Any hints/suggestions?

you can do stuffs with `java.util.Calendar` class, but I couldn't understand what is `quarter of an hour format`? More input and output may help? — sanbhat, Mar 06 '14 at 07:59
@sanbhat 12:05:15 will be rounded to 12:00:00 12:27 will be rounded to 12:30 etc — CodeFanatic, Mar 06 '14 at 08:02

score 3 · Answer 1 · answered Mar 06 '14 at 08:01

3

Use a Calendar object, then you can and manipulate the indvidual fields

  int min = cal.get (Calendar.MINUTE);

  int val = min / 15;  // or what ever logic you have.

answered Mar 06 '14 at 08:01

Scary Wombat

44,617
6
35
64

Rafael Winterhalter · Accepted Answer · 2014-03-06T08:20:07.137

2

Up to release version 7, Java comes with a terrible date and time API. Many developers therefore choose to use Joda time instead. It is a very common third-party dependency in many projects.

Using Joda time, you can do the following:

 Date toQuaterOfHour(Date date) {
   LocalDateTime ldt = new LocalDateTime(date.getTime());
   int quater = ldt.getMinuteOfHour() / 15;
   return ldt.withMinuteOfHour(quater * 15).toDate();
 }

Java 8 comes with a date and time API that is similar to that of Joda time.

edited Mar 06 '14 at 08:20

answered Mar 06 '14 at 08:02

Rafael Winterhalter

42,759
13
108
192

Basically. The migration should be rather easy due to the similarity of the APIs. Package-wise, Joda time and the new Java time API live in different name spaces. Also, some of the methods have different names as visible from: http://download.java.net/jdk8/docs/api/java/time/LocalDateTime.html - An example would be the method `withMinute` instead of `withMinuteOfHour`. – Rafael Winterhalter Mar 06 '14 at 08:09

score 0 · Answer 3 · answered Mar 06 '14 at 08:01

0

First of all, joda-time is battle tested well known solution for working with date/times in Java, so if you can push it into your project, do it (or at least try).

Second, I can help you with that, but please put here fully qualified name of object you are using. Date in java.util is mostly deprecated, so I would suggest looking on GregorianCalendar object (included in JDK) for date/time manipulation.

answered Mar 06 '14 at 08:01

apocalypz

1,180
1
8
11

I think this is just a comment. – Scary Wombat Mar 06 '14 at 08:04
You're right, next-time I provide sample code as well :) – apocalypz Mar 06 '14 at 08:06
But what is deprecated in java.util.Date has been deprecated since 1.1 – Scary Wombat Mar 06 '14 at 08:14
and ? I state otherwise ? – apocalypz Mar 06 '14 at 08:16
Just adding a comment to your comment. – Scary Wombat Mar 06 '14 at 08:18

score 0 · Answer 4 · answered Mar 06 '14 at 08:26

You may use simple arithmetic like this:

long millis = 15 * 60 * 1000;
long now = System.currentTimeMillis();
long rest = now % millis;
long quarter = now + (rest == 0 ? 0 : rest >= millis / 2 ? millis - rest : -rest);

System.out.println("Original: " + new Date(now));
System.out.println("Quarter: " + new Date(quarter));

Use the class SimpleDateFormat and choose the output format of your choice.

convert Date to a quarter of an hour type JAVA

4 Answers4