Date calculation using formula

I am looking to add a date 6 months from a specific date i insert, but the 6 month date must fall on a weekday, if the date falls on a weekend, I need it to add the weekday date before the date I enter. For example if I insert a date as the 2 January, and the 6 month date is 2 July, if this falls on a Saturday or Sunday, I need it to return the date on the Friday.