Gets the default translated date format. The function constructs a new string interpreting the with_weekday, with_day and with_year parameters so that it can be used with formatting functions like GLib.DateTime.format.
As the Granite.DateTime.get_default_time_format, the returned string is formatted, translated and is also mostly used to display the date in various user interfaces like the date displayed in the top panel.
if the returned string should contain the abbreviated weekday name
if the returned string should contain contain the day of the month as a decimal number (range 1 to 31)
if the returned string should contain the year as a decimal number including the century
returns the formatted and located date string. If for some reason, the function could not determine the format to use, an empty string will be returned.