diff -Naur Src.orig/calendar.c Src/calendar.c
--- Src.orig/calendar.c	2007-01-15 01:14:32.000000000 +0100
+++ Src/calendar.c	2020-03-29 13:25:39.390760510 +0200
@@ -1,5 +1,10 @@
 #include "calendar.h"
 
+time_t  modtime;
+struct  calobj* calRoot;
+int     xr, yr;
+int     datetype[32][2];
+
 int  get_datetype(int day){return datetype[day][0];}
 
 /*------------------------------------------------------
diff -Naur Src.orig/calendarfunc.c Src/calendarfunc.c
--- Src.orig/calendarfunc.c	2003-07-13 16:41:02.000000000 +0200
+++ Src/calendarfunc.c	2020-03-29 13:24:07.630789052 +0200
@@ -24,6 +24,7 @@
 #include <stdio.h>
 
 
+int     datemoon[200][2];
 
 long persian_jdn(struct icaltimetype dt)
 {
diff -Naur Src.orig/calendarfunc.h Src/calendarfunc.h
--- Src.orig/calendarfunc.h	2003-07-15 17:19:43.000000000 +0200
+++ Src/calendarfunc.h	2020-03-29 13:23:23.468802848 +0200
@@ -70,5 +70,5 @@
 
 int Ceil(float number);
 
-int     datemoon[200][2];   /* hashtable for moonphase.[jdn%32][0] stores moonphase of day jdn, 
+extern int     datemoon[200][2];   /* hashtable for moonphase.[jdn%32][0] stores moonphase of day jdn, 
 			    [jdn%32][1] stores jdn. */
diff -Naur Src.orig/calendar.h Src/calendar.h
--- Src.orig/calendar.h	2007-01-15 01:13:50.000000000 +0100
+++ Src/calendar.h	2020-03-29 13:25:57.657754851 +0200
@@ -5,10 +5,10 @@
 #include <sys/stat.h>
 
 
-time_t  modtime;              /* modified time of icalendar file */
-struct  calobj* calRoot;  /* 1st element in list of calendar obj*/
-int     xr, yr;               /*evil hack for moving dayview window*/
-int     datetype[32][2];      /* hashtable for coloring days.[jdn%32][0] stores color of day jdn, 
+extern time_t  modtime;              /* modified time of icalendar file */
+extern struct  calobj* calRoot;  /* 1st element in list of calendar obj*/
+extern int     xr, yr;               /*evil hack for moving dayview window*/
+extern int     datetype[32][2];      /* hashtable for coloring days.[jdn%32][0] stores color of day jdn, 
 				 [jdn%32][1] stores jdn. */
 struct calobj{
     struct icaltimetype start;
diff -Naur Src.orig/settings.c Src/settings.c
--- Src.orig/settings.c	2003-07-15 17:22:51.000000000 +0200
+++ Src/settings.c	2020-03-29 13:26:31.673744323 +0200
@@ -1,4 +1,14 @@
 #include "settings.h"
+
+char    rcfile[250];
+char    icsfile[250];
+char    application[250];
+int     start_of_week;
+char*   daystr[8];
+int     appicon;
+int     lang;
+int     debug;
+
 void set_lang(int language){lang = language;}
 void setAppicon(int app){appicon = app;}
 void enter_callback( GtkWidget *widget, GtkWidget *entry ){ 
diff -Naur Src.orig/settings.h Src/settings.h
--- Src.orig/settings.h	2006-09-15 11:56:12.000000000 +0200
+++ Src/settings.h	2020-03-29 13:26:37.732742450 +0200
@@ -7,14 +7,14 @@
 
 
 
-char    rcfile[250];       /* location of settings file */
-char    icsfile[250];      /* location of icalendar file */
-char    application[250];  /* command for starting external application */
-int     start_of_week; /* defines the first day of week */
-char*   daystr[8];
-int     appicon;       /* sets the application icon evol(0) moz(1) other(2)*/
-int     lang;          /* defines the language 0:english(default) 1:farsi */
-int     debug;         /* debug mode off(0) or on(1) */
+extern char    rcfile[250];       /* location of settings file */
+extern char    icsfile[250];      /* location of icalendar file */
+extern char    application[250];  /* command for starting external application */
+extern int     start_of_week; /* defines the first day of week */
+extern char*   daystr[8];
+extern int     appicon;       /* sets the application icon evol(0) moz(1) other(2)*/
+extern int     lang;          /* defines the language 0:english(default) 1:farsi */
+extern int     debug;         /* debug mode off(0) or on(1) */
 
 
 void destroy (GtkWidget * widget, gpointer data);