Denver has been had by United guys at under 1.5 years just recently.

Could be longer or shorter for new hires now. Plenty of guys want to get back to Denver, but there is also going to be a lot of new instructor jobs with the consolidation of the two training centers (IaH and DEN) to DEN only.
65 new 737-700 starting next year and a network plan to reduce RJ flying, put a good focus on Denver which means more spots.

Not to mention super senior DEN FOs that can hold captain and several have been doing so, plus lots of new widebodys coming at a fast pace.

So overall hard to give an exact as you never know what people will bid, but under 2 years I'd say is definitely looking realistic.

and you can make a lot more money as well.