Use CLOCK_REALTIME.

xlap.h

@@ -153,7 +153,7 @@ typedef char XlapTimestampPlaceholder;
  */
 #ifdef XLAP
 #	define XlapTimeStampClock(sck, kind, seqno, id) do { \
-            clock_gettime(CLOCK_MONOTONIC, &atomic_load_explicit(&(sck)->tstable[kind], memory_order_acquire)->rows[(seqno) % TS_ROWS].time[ts_##id].actual.t); \
+            clock_gettime(CLOCK_REALTIME, &atomic_load_explicit(&(sck)->tstable[kind], memory_order_acquire)->rows[(seqno) % TS_ROWS].time[ts_##id].actual.t); \
         } while (0)
 #else /* XLAP */
 #	define XlapTimeStampClock(sck, kind, seqno, id) do { \