How to get last day of a month from a given date?

Question

For example, the given date is 04/04/1924 and I want to find out the last day of February of the year 1924.

I came up with the add_month but it

Answer 1

to get the selected month and year last day:

SELECT TO_CHAR(LAST_DAY(TO_DATE(:X_THE_MONTH ||'/01/' || :X_THE_YEAR,'MM/DD/YYYY')), 'dd') FROM DUAL