All right already. I know this one sounds subjective and snooty. Not to mention pretentious. But bear with me, we’re only talking semantics here.
Of course, all of us who work at an office have our "lunch hour," — an hour more or less to eat. But, instead of saying, "during my lunch hour," substitute "at lunch," or "during lunch," or "about 12:30" — anything except "my lunch HOUR."
"Why?" you understandably ask. Because, by saying "HOUR," you are diminishing yourself. Between the lines, the listener hears that somebody above you dictates your schedule.
But, by using one of the suggested substitute phrases, you sound self-directed, not directed by someone else. No matter what professional position you hold, or how structured your day, you have the liberty to think and speak like the Captain of Your Own Ship. And Captains aren't told how long they have for lunch.