I'm trying to set a date of "the 7th of the following month, with a cutoff of the 24th of the month", calculating from a field called "CCPostDate".  The following calculation works perfectly in Excel, and it appears that all the same functions are available in Forms. 

=IF(DAY(CCPostDate)<=24,EDATE(CONCATENATE(MONTH(CCPostDate),"/07/",YEAR(CCPostDate)),1),EDATE(CONCATENATE(MONTH(CCPostDate),"/07/",YEAR(CCPostDate)),2))

The formula seems to validate fine when I refresh the form design, but when I do a preview form, I get the following error;

This field contains a calculation error.
References: Credit Card Posting Date, Credit Card Posting Date, Credit Card Posting Date, Credit Card Posting Date, Credit Card Posting Date

I was using the following formula, but I ended up with dates like 13/07/2017 and 14/07/2017.

=CONCATENATE((IF((DAY(CCPostDate))<=24,SUM((MONTH(CCPostDate))+1),SUM((MONTH(CCPostDate))+2))),"/07/",(YEAR(CCPostDate)))

Any ideas would be appreciated!