diff --git a/network.c b/network.c
--- a/network.c
+++ b/network.c
@@ -10,6 +10,7 @@
 #include "network_data.h"
 #include "command.h"
 #include "variables.h"
+#include "date.h"
 
 #if defined(WITH_REV)
 	extern const char _openttd_revision[];