It is just common sense to add the date, be it the date of manufacture or the expiry. Worrying if other vendors aren't doing that.
Yeah I would have thought it's something they would put on the bottle/packaging regardless of whether it's a requirement! It does make me question why they wouldnt state a date but I'm not too worried as the juice seems ok, as long as it's not going to do me any harm to vape it! I just wanted to check it wasnt a requirement as that would worry me if it was