DateTimePicker adjustments

Hi Guys,

It is probably simple, but I am far away form being a coder.
I have added the DATE option to some of the products on OC 2.0.
When I want to choose the date I have to press the button next to the form and the calendar appears allowing me to select the date that I want..

Question 1 is: How could I make the calendar show automatically when the page loads and not by clicking the button.
Question 2: The calendar allows me to select only one date. Is it possible to select a few different dates on the same calendar and have them appended to the date form ?

I've attached an img to illustrate what I would need.

Thank you!