wcs A pointer to the resultant wide-character string. maxsize The maximum number of wide characters to be stored in the resultant string. format A pointer to the string that controls the format of the output string. For the XPG4 interface, this argument is a pointer to a constant character string. For the ISO C interface, it is a pointer to a constant wide-character string. timeptr A pointer to the local time structure. The tm structure is defined in the <time.h> header file.