Datetime picker doesn't have seconds option

[ricardosobrado]

Hi! I think this library is great, congratulations to all who support it!
I would like to ask if there is any chance to add the seconds to Datetime picker? Also, another interesting feature would be to allow to customize the header of the datetime picker. This would allow for example to configure buttons to navigate to current date, next month, ...

Please let me know your thoughts! I would be happy to contribute also for these developments!
Cheers! :)

[nzbin]

I will be happy if anyone give me a PR.

[AlexElin]

I suppose the reason is that the Material Design spec says about hours and minutes, not seconds.

Users can select hours, minutes, or periods of time