Get all full hours of every day of a year

Question

I need to get / print on command line every full hour of every day of a given year, e.g. 2011 but I am struggling to code it in Java.

Has anybody ever coded this issue?

Probably time-zone dependent, too. – Thilo Aug 21 '12 at 09:48 — Thilo, Aug 21 '12 at 09:48
yes. ;) Is there anything more specific you want to know? – Peter Lawrey Aug 21 '12 at 09:51 — Peter Lawrey, Aug 21 '12 at 09:51

Marko Topolnik · Accepted Answer · 2012-08-21T10:09:19.727

7

This should work:

final DateFormat df = DateFormat.getDateTimeInstance();
final Calendar c = Calendar.getInstance();
c.clear();
for (c.set(2011, Calendar.JANUARY, 1, 0, 0, 0);
     c.get(Calendar.YEAR) == 2011;
     c.add(Calendar.HOUR_OF_DAY, 1))
  System.out.println(df.format(c.getTime()));

Notice, for example, this subtlety in the output:

Oct 30, 2011 12:00:00 AM
Oct 30, 2011 1:00:00 AM
Oct 30, 2011 2:00:00 AM
Oct 30, 2011 2:00:00 AM
Oct 30, 2011 3:00:00 AM

edited Aug 21 '12 at 10:09

answered Aug 21 '12 at 09:54

Marko Topolnik

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2

Could you also use c.add(c.HOUR_OF_DAY, 1); instead? – MadProgrammer Aug 21 '12 at 09:57
Wow, +1 for a new breed of for loops – Mazyod Aug 21 '12 at 10:14
1

@Mazyod Kernighan and Ritchie would've been proud of me :) – Marko Topolnik Aug 21 '12 at 10:24

nilsmagnus · Answer 2 · 2012-08-21T10:50:16.427

1

you could easily solve this by using the joda-time library:

    org.joda.time.Hours.hoursBetween(
        new org.joda.time.DateMidnight(2012,1,1).toLocalDate(), 
        new org.joda.time.DateMidnight(2013,1,1).toLocalDate()
      ).getHours();

edited Aug 21 '12 at 10:50

answered Aug 21 '12 at 10:37

nilsmagnus

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score 0 · Answer 3 · answered Aug 21 '12 at 09:53

0

Use Calendar, and loop day after day to manage a "String quoted" as you like by parameter needed,

You can put each line day (usually separated by a comma) in a file

answered Aug 21 '12 at 09:53

cl-r

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Get all full hours of every day of a year

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