Routine

More commonly used word for that is chore.
Hey, how about a round of golf Saturday morning? Sorry, Bob, I can't.
I gotta chores to do. Maybe in the afternoon if it's OK with you.
I never heard I gotta routine to do.

Colonel, Liutenant, Sergeant are all army ranks. Colonel in the navy is Captain.
Sergeant in the navy is Petty officer. Liutenant in the navy is Lt. Jg(Lieutenant
Junior grade) oir Lieutenant.