Index: source/lib/timer.cpp
===================================================================
--- 0ad-0.0.23b_alpha/source/lib/timer.cpp
+++ 0ad-0.0.23b_alpha/source/lib/timer.cpp
@@ -77,7 +77,7 @@
 #if OS_WIN
 	// whrt_Time starts at zero, nothing needs to be done.
 #elif HAVE_CLOCK_GETTIME
-	(void)clock_gettime(CLOCK_REALTIME, &start);
+	(void)clock_gettime(CLOCK_MONOTONIC, &start);
 #elif HAVE_GETTIMEOFDAY
 	gettimeofday(&start, 0);
 #endif
@@ -104,7 +104,7 @@
 #elif HAVE_CLOCK_GETTIME
 	ENSURE(start.tv_sec || start.tv_nsec);	// must have called timer_LatchStartTime first
 	struct timespec cur;
-	(void)clock_gettime(CLOCK_REALTIME, &cur);
+	(void)clock_gettime(CLOCK_MONOTONIC, &cur);
 	t = (cur.tv_sec - start.tv_sec) + (cur.tv_nsec - start.tv_nsec)*1e-9;
 #elif HAVE_GETTIMEOFDAY
 	ENSURE(start.tv_sec || start.tv_usec);	// must have called timer_LatchStartTime first
@@ -129,7 +129,7 @@
 	resolution = whrt_Resolution();
 #elif HAVE_CLOCK_GETTIME
 	struct timespec ts;
-	if(clock_getres(CLOCK_REALTIME, &ts) == 0)
+	if(clock_getres(CLOCK_MONOTONIC, &ts) == 0)
 		resolution = ts.tv_nsec * 1e-9;
 #else
 	const double t0 = timer_Time();