Had the same "open" surgery 6 years ago. Terrible impingement tore rotator...spur shreadded the tendon...lots of repair...
Had it done Aug 27th...and was shooting my huntin weight bow by Nov!
Each person is different. Each surgery/surgeon is different and recovery is also different.
My surgeon told me "be 6 months till you're back to normal activity..." Then it was "be a year till you are totally symptom free".
They don't know...
Here's my suggestion: Make sure you find out where the line is between PAIN and DAMAGE to what they fixed! I pushed them for that...and they responded. Most folks don't want much pain...but pain can be either your body being angry at you for the surgery and you can push through it..or...OR..it's your body's way of tellin you that you're screwing up big time and damaging what's been fixed.
Make them tell you what is what...then do what you are allowed to do with a vengance. You'll be back out there sooner'n you think! And you'll be so freakin busy working hard to get better...doing what you're allowed to do as often as allowed...you won't have time to be sorry or bored!
Prayers for a great surgery, a doc that tells it like it is and the will to endure all that lies ahead.
Keep the Son in your eyes!