Returns true if the #GDate represents an existing day. The date must not contain garbage; it should have been initialized with glib.date.Date.clear if it wasn't allocated by one of the glib.date.Date.new_ variants.
Whether the date is valid
Returns true if the #GDate represents an existing day. The date must not contain garbage; it should have been initialized with glib.date.Date.clear if it wasn't allocated by one of the glib.date.Date.new_ variants.