Their time picker is fine as it's little more than a combo box for the end user. Their date picker however isn't any better than any other I've seen and almost all of them have usability or discoverability problems. In this case entering dates in the far past or future requires a lot of clicks, and for me significantly more effort than typing the date. It's also not terribly discoverable as there's not a visual indication that I could see indicating the year portion of the widget was clickable and could be used to drill down into selecting other years, decades, etc.