Depends on the surgery, and if any complications arise.
If they are going in from the side as opposed to opening you chest cavity at your sternum the time in the hospital is regularly less.
Pretty standard is 2-3 day for the less invasive side procedure, and 4-6 days for the open chest procedure.
If the later procedure is done, you will spend the first 2 days in a more intensive room, where you will be pretty much under constant monitoring, and then moved to a recovery wing for the next 2 to 3 days until discharged.
This is from a US standard, I am not sure the hospital standards for other countries.
Good luck and best wishes on the surgery.