The standard control could use improvements (hm, I'd probably vote for a dictation button that lets me say "next Wednesday" instead of doing math), and we need handsome alternatives like this to nudge it forward. Because user familiarity is critical, I'd prefer to see an implementation that adds functionality with minimal changes to the way we all robotically enter a date/time/whatever. A subclass, if possible.
My portfolio is filled with regrets where I chose something interesting over something obvious.
My portfolio is filled with regrets where I chose something interesting over something obvious.