Adjusting my plan

I am adjusting things a tiny bit. I've promised myself 30 min of cardio everyday. I need to promise only 6 days. I am WAY to tired on Tuesdays (which is my longest day of the week) to get this in. It happened last week and again today. It's already 9:30, we are just getting the kids to bed and I am just ready to crash myself. So I don't think there is anything wrong with giving myself that 1 day to catch up. maybe it's just what my body is craving??