Handling non understandable behaviour of Java date formats.

Question

As I am not expert in handling of dates in java but I am unable to understand this behaviour.
Here is my code

Date from = new SimpleDateFormat("dd/MM/yyyy").parse("05/07/2013");
System.out.println(from);

which gave me this output

Sat Jul 05 00:07:00 PKT 2013

And this is 2nd another code snippet

Date from = new SimpleDateFormat("dd/mm/yyyy").parse("05/07/2013");
System.out.println(from);

which gave me this output:
Sat Jan 05 00:07:00 PKT 2013

Now the thing which is considerable is format.
This format dd/MM/yyyy which have MM gave me correct output but this format dd/mm/yyyy which have small mm gave me wrong output (always give jan in month).I read the doc where it is mentioned that samll m is for minutes and capital M is for month
My question is Can I never use small m here? if no , then why it is giving the result and on which basis it is giving jan everytime

I know this is a basic question but after searching and after not finding any understandable thing , I posted it.Thanks

Answer 1

Date from = new SimpleDateFormat("dd/mm/yyyy").parse("05/07/2013");

that mm in your format is for minutes. MM is for month.

Those formatting placeholders are fixed. small m is always for minutes. And it's January because this is the default Month value.

Answer 2

mm is for minutes so you do not have any month in your date. Thus, I guess that the month is initialized to 0 (Jan)

Answer 3

The reason it does not fail is because by default the formatter is lenient. If you want it to fail then setLenient(false) on the formatter object.

Although I do not think it will fail in your case as in your example it will read 07 as minutes.

Answer 4

When using

Date from = new SimpleDateFormat("dd/mm/yyyy").parse("05/07/2013");

the simple mm is for minutes therefore i think the value for month is assumed to be 0 so it gives Jan as the default value so use MM for month.

Answer 5

I guess it comes from calendar.clear() which will point to 1 Jan 1970. Then it adds you parsed data = 2013 years (YY), 5 days (dd) and 7 minutes (mm). Use MM for month