creates a new date formatting method
| format | string|function | a date format |
| utc | boolean | convert local time to a string in UTC format |
| function | a formatting function |
var myformat = webix.Date.dateToStr("%m - %d");
var text = myformat(new Date());
// or directly
{
view:"datepicker",
format: webix.Date.dateToStr("%d/%m/%y")
}