Non ci avevo pensato, bastava fare un cast:

codice:
static char **daytab;
daytab=(char**)malloc(2*sizeof(char*));
daytab[0]=(char*)(char[]){0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
daytab[1]=(char*)(char[]){0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
Non si finisce mai di imparare