Currently, the Indianapolis Colts veteran players under contract are involved in voluntary offseason workouts. Those workouts began on April 15th, and they mostly involve meetings with the coaches, weight training, and getting to know everyone that figures to be on the 2013 roster.
As far as how the rest of the offseason calendar goes:
May 10-12- Rookie Minicamp
OTA Offseason Workouts- May 20-22, May 28-30, June 3-6
Mandatory Minicamp- June 11-13
And then, there is this:
#Colts announce an open minicamp practice on Wednesday, June 12. Doors open at 2:00 p.m. and admission is free. Practice starts at 5:30 p.m.
— Kevin Bowen (@KBowenColts) April 29, 2013
Following the conclusion of the mandatory minicamp, we basically are in a holding pattern until the beginning of Training Camp in late-July.