try this

Fork of DS1307_RTC by Joseph Bradshaw

Revision:
2:a9a0784930bd
Parent:
1:95a90bac5d6d
--- a/DS1307_RTC.h	Sat Nov 01 14:05:25 2014 +0000
+++ b/DS1307_RTC.h	Sat Nov 01 14:56:37 2014 +0000
@@ -20,8 +20,8 @@
     void set_RTC_time_UTC(float utc_time, int timezone);
     void get_RTC_time(char *str);        
 
-    char  *Day[];
-    char  *Mon[];
+//    char  *Day[];
+//    char  *Mon[];
      
     int rtc_sec;
     int rtc_minute;