What is the difference between Calendar.WEEK_OF_MONTH and Calendar.DAY_OF_WEEK_IN_MONTH in Java's Calendar class?

Question

Java's Calendar class provides for two fields: WEEK_OF_MONTH and DAY_OF_WEEK_IN_MONTH. Can someone explain the difference to me? It seems that they both return the same value when tested using the code below:

Calendar date = Calendar.getInstance();
date.set(2011,5,29);
int weekNo1 = date.get(Calendar.WEEK_OF_MONTH);
int weekNo2 = date.get(Calendar.DAY_OF_WEEK_IN_MONTH);

Answer 1

The difference is that DAY_OF_WEEK_IN_MONTH provides the number of times the weekday has occurred during the month and WEEK_OF_MONTH just returns the week number within the current month. Think of it this way, if the month starts on a Wednesday, the first Monday will occur during the second week of the month. The value for DAY_OF_WEEK_IN_MONTH for that Monday would be 1, but the WEEK_OF_MONTH would be 2.

Answer 2

• Calendar.WEEK_OF_MONTH simply returns "Current week number in current month"
• Calendar.DAY_OF_WEEK simply returns "Current day number in current week starting on last Sunday"
• Calendar.DAY_OF_WEEK_IN_MONTH returns "N if current day is Nth day of month" say "3 if today is 3rd Wednesday in month"

So I am writing this on 21st December 2016:

And this is what I am getting:

Calendar today = Calendar.getInstance();
System.out.println(today.get(Calendar.DAY_OF_WEEK));          //outputs 4, as today is 4th day in this week which started on 18
System.out.println(today.get(Calendar.DAY_OF_WEEK_IN_MONTH)); //outputs 3, as today is "3rd Wednesday of this month". Earlier two wednesday were on 7th and 14th
System.out.println(today.get(Calendar.WEEK_OF_MONTH));        //outputs 4, as currently 4th week of a month is running

Answer 3

I found all of the other docs confusing, so for any Microsoft developers like myself this one might be clear for you, as it was for me:

http://msdn.microsoft.com/en-us/library/aa986432(v=vs.80).aspx

A constant representing a value for how many times a given day has occurred in the month.

Answer 4

Week of Month is the week within the current month starting from sundays how many weeks have there been.

Day of week of month is the day 5 would be Thursday, 1 sunday ect.