diff --git a/services/surfaceflinger/layerproto/layerstrace.proto b/services/surfaceflinger/layerproto/layerstrace.proto
index 7def024..804a499 100644
--- a/services/surfaceflinger/layerproto/layerstrace.proto
+++ b/services/surfaceflinger/layerproto/layerstrace.proto
@@ -38,6 +38,10 @@
 
     optional fixed64 magic_number = 1;  /* Must be the first field, set to value in MagicNumber */
     repeated LayersTraceProto entry = 2;
+
+    /* offset between real-time clock and elapsed time clock in nanoseconds.
+       Calculated as: systemTime(SYSTEM_TIME_REALTIME) - systemTime(SYSTEM_TIME_MONOTONIC) */
+    optional fixed64 real_to_elapsed_time_offset_nanos = 3;
 }
 
 /* one layers trace entry. */
diff --git a/services/surfaceflinger/layerproto/transactions.proto b/services/surfaceflinger/layerproto/transactions.proto
index 4f99b19..49487ee 100644
--- a/services/surfaceflinger/layerproto/transactions.proto
+++ b/services/surfaceflinger/layerproto/transactions.proto
@@ -36,6 +36,10 @@
 
     fixed64 magic_number = 1; /* Must be the first field, set to value in MagicNumber */
     repeated TransactionTraceEntry entry = 2;
+
+    /* offset between real-time clock and elapsed time clock in nanoseconds.
+       Calculated as: systemTime(SYSTEM_TIME_REALTIME) - systemTime(SYSTEM_TIME_MONOTONIC) */
+    fixed64 real_to_elapsed_time_offset_nanos = 3;
 }
 
 message TransactionTraceEntry {