Not sure if anyone would find this useful. I was working on a flow that would send the daily countdown of an event to an arduino. I think other might find it useful. It is a two parter.
First I create flow to update the variable, I could not find a date function to do this any better. Basically every day a midnight increment the variable by 1. The notification was there to check if was really working, it is not need for this flow,
For the countdown I send the dayofyear variable to a Math thing were I use the day of the year of the event and subtract the variable. Then send an email as a "daily digest" every morning at 8:00 AM.