As a user, I want to navigate easily the full multi-year extent of the data-having days

[gsehrlich]

Is your feature request related to a problem? Please describe.
The datepicker now shows which days have data but only one month at a time, with no way to know in advance if going forward or backward in time will show you more data.

Describe the solution you'd like
Ideally we would use something like what @mnorelli suggested: an easy way to see an entire year at once, perhaps modeled off of Github's contributions graph. See Michael's Github page for an example: https://github.com/mnorelli?tab=overview&from=2016-12-01&to=2016-12-31. For MVP, even some text showing the earliest and latest dates with data, and maybe the quartiles or quintiles, would be hugely helpful. They could even be buttons that change the date when clicked.

For Developers

Affected Components
Map menu page

[gsehrlich]

There's also this whole-year datepicker. https://react.rocks/example/react-yearly-calendar