Putting the weekdays in the trigger would serve as a filter. As @ShadowFist pointed out, they have no merit on their own, as a separate trigger.
A filter is what conditions bring to the table, so putting a filter (condition) inside a trigger is maybe more intuitive, but at the downside of mixing concepts and duplicating similar concepts. If it were added, we’d still need a day of week filter as a condition.
I agree with the poster that it is weird that, when using a condition, you need to add a start and end time if you want a day of week condition. So for me, the logical way forward is to allow for a day of week filter that does not require you to also have a condition on time of day. That would be clean and in line with existing concepts, and more intuitive.
@petro now I am very curious why such improvement would not be accepted. That would be important to see before proposing a code change, I was inclined to contributing to that, but also don’t want to waste time if there is some reason already to decline it.