Calendar class time month not matching

Question

Calendar c = Calendar.getInstance();

System.out.println("Mili->>" + c.getTimeInMillis());

System.out.println("Month  ->>" + Calendar.MONTH);

Though I am getting correct time in millisec format, Month is showing as 2 (March??) Why so?

Below is output

Mili->>1434029840778

Month ->>2

Answer 1

What you want is the following idiom: c.get(Calendar.MONTH).

Calendar.MONTH per se is just an internal constant and will (hopefully) always return 2.

Example

// We're in June at the time of writing
// Months are 0-based so June == 5
Calendar c = Calendar.getInstance();
System.out.println(Calendar.MONTH);
System.out.println(c.get(Calendar.MONTH));

Output

2
5

See also: API

Answer 2

You are displaying the value of the Calendar.MONTH constant, hence 2.

Answer 3

You're getting calendar c from an instance but calendar from month with the Calendar object, get it from the instance too.

Also - Calendar starts from 0 as referenced here

In other news, use the new DateTime API in Java 8 or JODA time, they're much nicer.

Answer 4

tl;dr

int monthNumber = LocalDate.now().getMonth().getValue() ;  // 1-12 for January-December.

Avoid legacy date-time classes

The other Answers are outmoded. The terribly flawed legacy date-time classes such as Calendar & Date were years ago supplanted by the modern java.time classes defined in JSR 310.

java.time

If you want a count of milliseconds since the first moment of 1970 as seen with an offset from UTC of zero hours-minutes-seconds, use java.time.Instant class.

long millisSinceEpoch = Instant.now().toMillis() ;

Going the other direction:

Instant instant = Instant.ofMillis( millisSinceEpoch ) ;

If you want to know the month, you must specify the time zone by which you want to determine the date. For any given moment, the time and date varies around the globe by time zone. Therefore the month can vary too.

ZoneId z = ZoneId.of( "Asia/Tokyo" ) ;
ZonedDateTime zdt = instant.atZone( z ) ;

Interrogate for the month, an enum object Month.

Month month = zdt.getMonth() ;

Get the month number by asking the enum object for is definition order. Unlike the legacy Calendar class, java.time uses sane numbering: 1-12 for January-December. So March is 3, as you expected.

int monthNumber = month.getValue() ;

If you want to skip the count of milliseconds, and just want to know the current month, use LocalDate to capture the current date.

ZoneId z = ZoneId.of( "Africa/Casablanca" ) ;
LocalDate today = LocalDate.now( z ) ;
Month currentMonth = today.getMonth() ;
int monthNumber = currentMonth.getValue() ;

Or, collapse that code:

int monthNumber = 
    LocalDate
    .now( ZoneId.of( "Africa/Casablanca" ) )
    .getMonth()
    .getValue() ;