View Compilation Error

0_0_24154760_21822.c: In function 'main':
0_0_24154760_21822.c:8:14: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
  int a[2][13]{{0,31,28,31,30,31,31,30,31,30,31,30,31},
              ^
0_0_24154760_21822.c:8:53: error: expected ';' before '}' token
  int a[2][13]{{0,31,28,31,30,31,31,30,31,30,31,30,31},
                                                     ^
0_0_24154760_21822.c:8:54: error: expected expression before ',' token
  int a[2][13]{{0,31,28,31,30,31,31,30,31,30,31,30,31},
                                                      ^
0_0_24154760_21822.c:15:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int i=0;i<mon;i++){
  ^
0_0_24154760_21822.c:15:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_24154760_21822.c:16:10: error: 'a' undeclared (first use in this function)
    days+=a[run][i];
          ^
0_0_24154760_21822.c:16:10: note: each undeclared identifier is reported only once for each function it appears in