For months which have 30 days e.g. April, entering a date using the 31st day of that month is accepted.

[naz019]

To reproduce: Take any month which has only 30 days e.g. April and use the add command using the month's 31st day. Example: add t/income c/bonus a/9999999 d/31042022 i/54624624

An 'invalid date' error is expected but instead, the program accepts the date by correcting the date to the 30th day e.g. 30042022 when user keys in 31042022