This is an element in the main window. It is used to choose a date.
The Calendar is displayed like this:
To choose a date, click on the button to the right of the calendar: .
The Calendar will then open:
There are several possibilities:
Choice of year,
Choice of month,
Choice of day,
Choice of today’s date.
The definition of week numbers is defined by the Standard 8601 created by the International Standards Organization (ISO).
This standard defines that the first week of the year is that containing the first Thursday of the year.