Try something like this:
function valid = valid_date(year,month,day)
if ((isscalar(year) && year>0 ) && (isscalar(month) && month>0) && (isscalar(day) && day>0))
%For Leap year
if (((rem(year,4) == 0) && (rem(year,100) == 0) && (rem(year,400) == 0)) || ((rem(year,4) == 0) && (rem(year,100) ~= 0)))
valid_leap = true;
else
valid_leap = false;
end
% check for other months
if ismember(month,[1 3 5 7 8 10 12]) && (day <=31)
valid = true;
elseif ismember(month,[4 6 9 11]) && (day <= 30)
valid = true;
elseif (month == 2 && valid_leap == true && day <=29)
valid = true;
elseif (month == 2 && valid_leap == false && day <=28)
valid = true;
else
valid = false;
end
end
