Setting the year in Calendar

Question

I have the following piece of code.

SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/YYYY HH:mm");
Calendar cal = Calendar.getInstance();
cal.clear();
cal.set(Calendar.YEAR, 2016);
cal.set(Calendar.MONTH, 11);
cal.set(Calendar.DAY_OF_MONTH, 31);
cal.set(Calendar.HOUR_OF_DAY, 22);
Date start = cal.getTime();
System.out.println(dateFormat.format(start));
cal.set(Calendar.YEAR, 2017);
cal.set(Calendar.MONTH, 0);
cal.set(Calendar.DAY_OF_MONTH, 1);
cal.set(Calendar.HOUR_OF_DAY, 5);
Date end = cal.getTime();
System.out.println(dateFormat.format(end));

It prints:

31/12/2016 22:00
01/01/2016 05:00

I expect that the year of the second date is 2017. What is going on? I'm using Java 1.7.

I just ran your code and it seems fine, printed 2017, no problem. Can you update you code with the full version ? maybe something outside that can be influencing ? like thread ? — Josh, Dec 26 '16 at 13:03
Why do people keep using `YYYY` instead of `yyyy` without knowing what `YYYY` does? Unbelievable. In other words: starting using a proper pattern for printing your date. — Tom, Dec 26 '16 at 13:07
@Tom Because I didn't realise that was an option. Thanks to your very helpful comment, I went on to read the docs and I know understand my error. So thanks, I guess. — Auberon, Dec 26 '16 at 13:10
Auberon, it is *always* important to read the documentation, especially when passing "stuff" into the a constructor or a method. Please remember that for the future. — Tom, Dec 26 '16 at 13:15

Loris Securo · Accepted Answer · 2016-12-26T13:21:59.637

2

The correct date format should be dd/MM/yyyy HH:mm, not dd/MM/YYYY HH:mm, note the lower case y.

With that it works correctly.

From the docs:

y Year
Y Week year

Explanation of the difference between year and week year (from here):

A week year is a year where all the weeks in the year are whole weeks. [...] Basically, this guarantees that a program working on a week's data will not transition between years. [...] this also means that the beginning of the year may not start on the first of January.

edited Dec 26 '16 at 13:21

answered Dec 26 '16 at 13:09

Loris Securo

7,538
2
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This works. Thank you. From reading the docs, I couldn't understand what a "Week year" is. Do you care to elaborate? – Auberon Dec 26 '16 at 13:14
@Auberon added explanation – Loris Securo Dec 26 '16 at 13:22

score -1 · Answer 2 · answered Dec 26 '16 at 13:02

-1

This is working fine with the following dataFormat.

SimpleDateFormat dateFormat =  new SimpleDateFormat("MM/dd/yyyy hh:mm");

answered Dec 26 '16 at 13:02

SujitKumar

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1
10

it's up to you. how you will take your date format pattern. i simply given an example, because you didn't mentioned the data format in your question. please have common sense. – SujitKumar Dec 26 '16 at 15:03

Setting the year in Calendar

2 Answers2