It depends on what you mean by "date". A lot of people think that dating is a prelude to a serious relationship, and a lot think that a date is just something fun to do on a Saturday night.
I don't think there is much future in a serious relationship with a thirty year age difference. One person is at the beginning of their child rearing years, while the other is ending that era of their life.
If it's just for fun, then why not? There is no reason people of extremely different ages, backgrounds, religions, races, or what have you can't have fun together, and indulge in mutual interests. But their long term goals are apt to be very different and probably conflicting.
Everything has to be judged on an individual basis, with specific people and situations. Nothing can be decided in a general sense.