The repeat every 5 days might be tricky, but other than that everything you want to do is possible.
To clarify do you want valve 1 to run Monday, then Saturday, then Thursday? Or run valve 1 every Monday, as in 5 days after valve 3 completes on Wednesday?
Option 2 would be easy to accomplish, option one a bit more difficult. I just picked random days of the week for the program to run, if you want different days it wouldn’t change anything.
Totally forgot about interval programs, sorry david was right just set 2 back to back run times and you’re set. Sorry if I mislead you at all.