It was a chill interview with two people. They asked about my background, experience, and typical resume stuff. And a few questions about why I want to work at their company and what i know

I was contacted by a staffing agency. I had a phone "culture" screen on Monday and was set up for an on-site on Wednesday. Oxy does group interviews - two teams of two employees (two managers for the first, two technical people for the second) each lasting about a half-hour. The managers with which I spoke struck a generally friendly tone, and I recapped my background for the second one because I'd covered it with the first on the phone. The only question that gave me pause was "What was the date of your college degree?" I was told the reason for that question was because a 4-year degree is a requirement for employment at Oxy, and some candidates only list college time without a degree. The main issue I had at this was because it struck me as a convenient way to determine how old I was without asking me directly (which is illegal on a federal level). I'm still not convinced the question wasn't ethically or legally permissible, and having such as the rationale they had is a nice cover for the real motive behind the question (which could probably have been determined with a background check). Ironically, except for one of the interviewers, I'd have to say all the men with whom I spoke were easily over 40 years of age themselves (I am 56). I answered the question matter-of-factly but such a question puts the older candidate in a bind: answer it, and he/she may be screened out because of age (after the interview, of course; it would be unconscionably rude to do it right then and there); hem and haw or refuse to answer it, and the candidate looks uncooperative or that they're trying to hide it - in which case they could be barred from consideration for one of those reasons. I'd like to see Oxy drop this particular question from their interview regimen. It may be legal (somehow) but to an older candidate fortunate enough to get in front of their interviewers, it's a bad signal.