Returns a string containing the localized name of the weekday.
[in] Represents the day of the week, 0 = system default, 1 = Monday, 2= Tuesday etc.
[in] If zero then the full (non-abbreviated) weekday name is used. If non-zero, then the abbreviation for the weekday name is used.
[in] First day of the week, 0 = system default, 1 = Monday, 2 = Tuesday etc.
[in] VAR_CALENDAR_HIJRI is the only flag that can be set.
[out] Points to the formatted string that represents the variant.
The function returns one of the following:
Out of memory.
One or more of the arguments is invalid.