Can somebody please help me with the code for this question? I don't even know where to begin :(

Write the code for the following methods in the newDate class:
Public boolean validDate (int day, int month, int year)
The month can only be in the range 1-12 and a month must have the correct
Number of days e.g. 30.2.1997 is invalid because February can only have 28
Days, or 29 days if the year is a leap year.
This method must return true if the date is valid and false if the date is
Invalid.