Question

Well, I need get two values that represents the distance between two full dates-only (no hour/time)… On MySQL we have PERIOD_DIFF that get the diff between two dates (only month and year), but I need to include the day too.

I have two dates like:

• 2011-12-05 and 2012-01-10. After 2012-01-05 I have 1 full month, more 5 days.
• 2012-01-01 and 2012-03-01. I have 2 months and 0 day.
• 2012-02-29 and 2012-03-28¹. I have 0 month and 28 days. More: for 1 month, I need 2012-03-29.
• 2013-01-29 and 2013-02-28². I have 0 month and 30 days. More: for 1 month, I need 2013-03-01, because 2013-02-29 not exists.
• 2013-03-31 and 2013-04-30. Fix: really I have 0 month and 30 days. More: for 1 month, I need 2013-05-01, because 2013-04-31 not exists.

¹ 2012 is a leap year / bissexto;
² 2013 is not;

I don’t know what I need do exactly to solve that.

Answer 1

Set some variable for total difference in months to 0.

Use DATEDIFF to get the total difference in days between your start and end date.

For each month between your start and end month (if there are any months in between), use LAST_DAY and DATEDIFF to calculate the number of days for that month.

Subtract the number of days for that month from the total difference in days, and add 1 to the total difference in months.