It depends on whether the turkey is cooked or raw turkey.
For a cooked turkey you can leave it out safely for 2 hours and if the turkey is frozen and uncooked then you could leave it out for 1 to 3 hours to allow it to thaw out.
What I do when preparing to cook a turkey is to remove it from the freezer the day before cooking it and then let the turkey sit out on the counter for 4 hours.
This allows it to thaw some and it's still frozen enough to keep bacteria from growing on the turkey.
Then I place the frozen turkey into the refrigerator and then by the next day the turkey is usually thawed enough to cook.
It's best to have the turkey thawed as good as possible so that the oven will cook the turkey properly or even the turkey cooker.
Do not leave the cooked or uncooked turkey out longer than 4 hours though and if you don't plan to eat the cooked turkey within a couple hours it's best to refrigerate it.