Hi, I did not figure out the following formula myself, but was given the info by app software support person. This forumula calculates 6 months back from a date, but could be easily changed to plus 6 months, and just change the name of the date field.
To see what the date is 6 MONTHS ago (not 180 days ago) from the animal's dob:
(Date(DateAdd("m", -6, Date(Year({animal.dob}), Month({animal.dob}), Day({animal.dob})))))
Harriet in Ottawa