At SkyWest, you would get DTW right away in training on the CRJ, and you would probably be on reserve for a month to 6 weeks depending how soon you are eligible to bid for a schedule. Reserve means being within 2 hours of the airport, so 1:20 is doable if you bag is always packed and I. Your car ready to go. Once you get a line, you can do anything from a 1 day trip to a 4 day trip, but Detroit has mostly 3 and 4 day trips because it's mostly commuters.
In reserve, you'll be given reserve blocks of 12 hour on call availability periods, 18 days a month. The blocks will be anywhere from 1 day to 6 days in a row.
As a line holder, you'll fly a few days in a row with a few days off in between for anywhere between 11-18 days off a month (12-15 is more typical), with the ability to pick up extra flying on your days off.