It does! When the interval is 1 day 
very very useful!
I especially love the .+ behavior for x number of days as seen in my Github post. it goes from 26th to 29th back to 26th when you increase the days by 1… 
I don’t even know…
Edit: OH! I understand now what you’re saying… after literally counting it out I now see what is happening.
to be honest it just makes my head spin…
Side note, I also dislike when rescheduling the type of scheduler I set gets changed back to default… but that’s another matter entirely.