When Date/time attribute is selected, a new date field appears on the Attributes panel.
Choosing a Value for a Date/time Attribute
A Date/time field accepts all characters, but if you enter a wrong date format, or any character except numbers, field's boder will become red, to show you an invalid input.
By clicking on theCalendar icon on the right side of the text box of the attribute, a calendar will be displayed, allowing to select a date and time from the calendar.