Extended Date: Manipulate and format dates and times

This object can manipulate and format dates and times.

It can perform operations with given dates like adding a given amount of time to a date, as well compare two dates and return the difference of time between them.

The object can also format a date according to a given format string that determines which date and time elements will appear in the formatted string, as well the respective positions in the string.

It can also create a HTML table to show a calendar of a given month on a Web page.

A callback function may be called when the user picks a calendar date.