HelloBaby- I'm going to suggest the opposite, probably unpopular view based on similar experiences at my house:)
We try to do some "homework" each day. We typically schedule it at exactly the same time. I lay the homework by DS's plate so he may finish directly after breakfast. It's about ten minutes worth of work, usually math for skill building.
If I tried to keep the homework only several times a week without a specific schedule, DS would find all kinds of reasons, excuses not to comply- we would spend our time together arguing and it may or may not get done. This way, it's simply built into the daily routine.
If we're doing a camp and can't do the "after breakfast homework routine" then I do try to get him to do it (not every day) if I can catch him on a good day. Otherwise, I let it go.
For my DS, routine (same time, same place each day) is important. If something is critical, I don't give him room to argue or to think of why he "shouldn't" do it.
