I was setting a "Happy Christmas" automation. I could have set the automation time trigger to "YEAR-12-31", but using the last working day as a trigger is better. Firstly I searched on the community for this kind of formula. I could not find. So, I wanted to share with you.
The weekday number of the 29th day is important, since if it is friday, this day should be trigger date, since 31th is sunday, etc.
Also, if you have a better formula or find a problem in my formula, please share your comments.
IF(AND(WEEKDAY(YEAR(TODAY()) & "-12-29") = 5, YEAR(TODAY()) & "-12-29" = DATETIME_FORMAT(TODAY(),"YYYY-MM-DD")),1,
IF(AND(WEEKDAY(YEAR(TODAY()) & "-12-29") = 4, YEAR(TODAY()) & "-12-30" = DATETIME_FORMAT(TODAY(),"YYYY-MM-DD")),1,
IF(YEAR(TODAY()) & "-12-31" = TODAY(),1,0)))
