Is it possible to schedule concurrent requests at specific date

Hello,

I would like to schedule concurrent request with a list of date.

IS it possible to do this ? I try to do this with the scheduler but I can't choose multiple date for one concurrent request.

Maybe I can do this with Advanced schedule but the choice is grey in form.

In html form I try to do this with advanced schedule but I can't choose some specific day for each month.

Does someone know is it possible to schedule specific dates for a request without specific ?

Thanks,

Antoine