--- Simulator/Time/fg_time.cxx.orig	Mon Apr 19 13:18:31 1999
+++ Simulator/Time/fg_time.cxx	Sun Jun 27 19:34:43 1999
@@ -49,6 +49,13 @@
 #  include <sys/time.h>  // for get/setitimer, gettimeofday, struct timeval
 #endif
 
+// The next lines are to define BSD
+// See http://www.freebsd.org/handbook/porting.html for why we do this
+
+#if (defined(__unix__) || defined(unix)) && !defined(USG)
+#include <sys/param.h>
+#endif
+
 #include <Debug/logstream.hxx>
 #include <Astro/sky.hxx>
 #include <Astro/solarsystem.hxx>
@@ -366,6 +373,11 @@
     // For now we assume that if daylight is not defined in
     // /usr/include/time.h that we have a machine with a BSD behaving
     // mktime()
+#   ifdef BSD
+#       define USE_TIME_GM 1
+#   endif
+
+
 #   if !defined(HAVE_DAYLIGHT)
 #       define MK_TIME_IS_GMT 1
 #   endif
@@ -383,6 +395,10 @@
     mt.tm_sec = sec;
     mt.tm_isdst = -1; // let the system determine the proper time zone
 
+#   ifdef USE_TIME_GM
+    return ( timegm(&mt) );
+#   else
+
 #   if defined( MK_TIME_IS_GMT )
     return ( mktime(&mt) );
 #   else // ! defined ( MK_TIME_IS_GMT )
@@ -424,6 +440,7 @@
     return ( start_gmt );
 #   endif // ! defined( TIMEZONE_OFFSET_WORKS )
 #   endif // ! defined ( MK_TIME_IS_GMT )
+#   endif
 }
 
 // Fix up timezone if using ftime()
--- Tests/test-mktime.cxx.orig	Sun Jun 27 19:21:42 1999
+++ Tests/test-mktime.cxx	Sun Jun 27 19:34:13 1999
@@ -20,6 +20,12 @@
 #  include <sys/time.h>  // for get/setitimer, gettimeofday, struct timeval
 #endif
 
+// The next lines are to define BSD
+// See http://www.freebsd.org/handbook/porting.html for why we do this
+#if (defined(__unix__) || defined(unix)) && !defined(USG)
+#include <sys/param.h>
+#endif
+
 #define LST_MAGIC_TIME_1998 890481600
 
 
@@ -73,6 +79,8 @@
     mt.tm_sec = 0;
     mt.tm_isdst = -1; // let the system determine the proper time zone
 
+#   ifdef BSD
+    return ( timegm(&mt) );
 #   if defined( MK_TIME_IS_GMT )
     return ( mktime(&mt) );
 #   else // ! defined ( MK_TIME_IS_GMT )
@@ -110,6 +118,7 @@
     return ( start_gmt );
 #   endif // ! defined( TIMEZONE_OFFSET_WORKS )
 #   endif // ! defined ( MK_TIME_IS_GMT )
+#   endif
 }