I think it looks terrific. I really like the notion of trying horizontal vs vertical scrolling.

Plus, I'm a big fan of reinventing the wheel. The final chapter of date pickers has not been written, IMHO, and am grateful for these types of experiments. I can easily imagine a "cover flow" inspired picker being great for certain use cases, like buying tickets.

Per @yoz-y down thread, I agree with need for text input. I like Fantastical's approach. Had hoped it'd become more common.