c$++$ member function It sets the Date's year to $1900$ if the year parameter is less than $1900.$

It sets the Date's month to $1$ if the month parameter is outside the range of $1$ to $12.$

It sets the Date's day to $1$ if the day parameter is outside the range of days for the specific month

Check if date is within day range of month. February will only have $28$ days, other months have either $30$ or $31$ days.