Using sscanf for dates in C

Sscanf with following does NOT WORK
void change_date_format(char *date_vlaue, char *fmt)
{
char day[2], month[2], year[4];
sscanf (date_value “%2s/%2s/%4s”, day, month, year);
}

Always use the following method:
void change_date_format(char *date_value, char *fmt)
{
int day, month, year;
sscanf (date_value, “%2d/%2d/%4d”, day, month, year);
sprintf (date_value, “%02d/%02d/%04d”, month, day, year);
}