Opening hours first and last Sunday of the month

I am trying to correct the opening hours for a shop is missing hours for Sundays. It is currently tagged:
“Mo-Th 10:00-18:00; Fr 10:00-19:00; Sa 10:00-17:00”. I would to add that on the first and last Sunday of the month it is open 11.00 - 16.00. Is it possible to add this?

Hello @Lostmonkey ,

yes you can use Su[1] for first sunday of month and Su[-1] for last sunday of month.

It could be:
Mo-Th 10:00-18:00; Fr 10:00-19:00; Sa 10:00-17:00; Su[1] 11:00-16:00; Su[-1] 11:00-16:00

More info:

and also :

Don’t forget you can test the syntax at various webpages, for instance this one: