How to utilize date add function in Google spreadsheet?

Solution 1:

I like to keep it simple. If A1 holds the date and B1 holds the number of months to add, then

=date(year(A1),month(A1)+B1,day(A1))

would calculate the required result. The same way could be used for days or years

Solution 2:

1. To extract a numeric value out of your string you can use these 2 functions (Assuming you have your value in cell 'A1'):

   =VALUE(REGEXEXTRACT(A1, "\d+"))

   This will get you a numeric value.

2. I've found no date add function in docs, but you can convert your date into internal date number and then add days number (If your value is in cell 'A2'):

   =DATEVALUE(A2) + 30

I hope this will help.