Эх, сразу видно посонов, не ковырявших исходники
#include "common.h"
static char *date = __DATE__ ;
static char *mon[12] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
static char mond[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
//...