Inline date edit with nojQuery

Inline Datepicker with vanilla JavaScript

I do write a lot of frontend, despite fact that I’m born to be backend guy. Long story short - we do have a lot of inline editing features especially elements like dates are pretty painful. HTML5 Introduced input type=date which is good enough to cover most of the cases, and we no longer need ugly and slow .datepicker() component from jQuery od 3rd party suppliers.

So if you do have edit you can just use <input type="date" value="yyyy-mm-dd"> field, and nice calendar will pop up. But we are looking for inline solution.