if option with weekend and date serial number

I have a date serial number x. If the number is a weekend then x+3, if the number is not a weekend then x +1. how can i put this as code?

Answer 1

[Walter Roberson]

output = x + 1 + 2 * isweekend( datetime(x, 'convertfrom', 'datenum') );

or

output = x + 1 + 2 * ismember(weekday(x), [1 7]);