@CalgaryBen good to know of a solution that works and can be recommended to Apple users. I suppose they can probably also get Apple to check for free if they take their device into an Apple Store?
Yes, "geniuses" at the Apple Store can provide this information if you have your device in-hand (i.e. they may be less willing if you just provide a SN or IMEI but no hardware). Their screen has the same information provided by imei.info and more. I recently did this as I was interested in the purchase date and warranty expiry on a used phone I had bought, and they happily provided the info. It was "free", but I was also there for a battery replacement (had scheduled an appointment), and had to navigate through Christmas shoppers and a packed store! While I'm cheap, not having to deal with crowds is worth the $2.99USD
I have to rescind my recommendation to use imei.info for Apple products, as I just used it, and the information provided is nowhere near as comprehensive as the report I obtained last year. YMMV. Not sure what changed, but the info they did provide is mostly the same as what can be obtained for free. I was looking for purchase and warranty dates, but this was missing. Apple's warranty checker also no longer provides specific dates, so maybe it's a change on the GSX side...