I too was puzzled by this. I have a lot of programs I need to set up, and all of them are daily, so I was looking for interval 1 day. Saves me about 7 clicks per program. Also, when I am done with all the programs, I have to double check every one of them to make sure I clicked all 7 days. Not a big deal, but why not let us put interval 1 as an option?