Common formulas for calculated fields

I'm linking to a Microsoft site which gives commonly used formulas for SharePoint calculated fields.  Which I recently used to subtract months from a date.  I started by simply subtracting a rough number of days from my date field but that isn't exactly the same as subtracting months since months have different numbers of days.  So instead of using

=IF([Go Live]<>"",[Go Live]-243,"")

I used

=IF([Go Live]<>"",DATE(YEAR([Go Live]),MONTH([Go Live])-8,DAY([Go Live])),"")

Which nicely subtracted 8 months from the field regardless of what the date was.  This same concept can be used to add/subtract years and/or days.  Here's the complete list of Examples of common formulas.