Any week you can get off.
By later in the season the bulls can be spooky depending on area drawn.410 the last few years has had alot cow permits issued and that can get the bulls all spooky due to more hunters.
You have a better chance at seeing bigger bulls later in the season cause they have left the cows and are getting bumped around more.That also can be bad cause they will see refuge on private with less huntig pressure or some of the worst country known to man.
Good luck
BBJ