Get the difference between two dates both In Months and days in sql

Question

I need to get the difference between two dates say if the difference is 84 days, I should probably have output as 2 months and 14 days, the code I have just gives the totals

Answer 1

SELECT   (MONTHS_BETWEEN(date2,date1) +  (datediff(day,date2,date1))/30) as num_months,
datediff(day,date2,date1) as diff_in_days  FROM  dual;

// You should replace date2 with TO_DATE('2012/03/25', 'YYYY/MM/DD')
// You should replace date1 with TO_DATE('2012/01/01', 'YYYY/MM/DD')
// To get you results

Answer 2

The solution I post will consider a month with 30 days

  select CONCAT (CONCAT (num_months,' MONTHS '), CONCAT ((days-(num_months)*30),' DAYS '))
  from ( 
  SELECT floor(Months_between(To_date('20120325', 'YYYYMMDD'),
   To_date('20120101', 'YYYYMMDD')))
   num_months,
   ( To_date('20120325', 'YYYYMMDD') - To_date('20120101', 'YYYYMMDD') )
   days
  FROM   dual);

Answer 3

See the query below (assumed @dt1 >= @dt2);

Declare @dt1 datetime = '2013-7-3'
Declare @dt2 datetime = '2013-5-2'

select abs(DATEDIFF(DD, @dt2, @dt1)) Days,
case when @dt1 >= @dt2
    then case when DAY(@dt2)<=DAY(@dt1)
        then Convert(varchar, DATEDIFF(MONTH, @dt2, @dt1)) + CONVERT(varchar, ' Month(s) ') + Convert(varchar, DAY(@dt1)-DAY(@dt2)) + CONVERT(varchar, 'Day(s).')
        else Convert(varchar, DATEDIFF(MONTH, @dt2, @dt1)-1) + CONVERT(varchar, ' Month(s) ') + convert(varchar, abs(DATEDIFF(DD, @dt1, DateAdd(Month, -1, @dt1))) - (DAY(@dt2)-DAY(@dt1))) + CONVERT(varchar, 'Day(s).')
    end
    else 'See asumption: @dt1 must be >= @dt2'
end In_Months_Days

Returns:

Days | In_Months_Days

62   |   2 Month(s) 1Day(s).

Answer 4

I think that your question is not defined well enough, for the following reason.

Answers relying on months_between have to deal with the following issue: that the function reports exactly one month between 2013-02-28 and 2013-03-31, and between 2013-01-28 and 2013-02-28, and between 2013-01-31 and 2013-02-28 (I suspect that some answerers have not used these functions in practice, or are now going to have to review some production code!)

This is documented behaviour, in which dates that are both the last in their respective months or which fall on the same day of the month are judged to be an integer number of months apart.

So, you get the same result of "1" when comparing 2013-02-28 with 2013-01-28 or with 2013-01-31, but comparing it with 2013-01-29 or 2013-01-30 gives 0.967741935484 and 0.935483870968 respectively -- so as one date approaches the other the difference reported by this function can increase.

If this is not an acceptable situation then you'll have to write a more complex function, or just rely on a calculation that assumes 30 (for example) days per month. In the latter case, how will you deal with 2013-02-28 and 2013-03-31?