1 files changed, 16 insertions, 0 deletions

diff --git a/src/include/gnunet_time_lib.h b/src/include/gnunet_time_lib.h
index b9c2d92f0..aa4e8d5db 100644
--- a/src/include/gnunet_time_lib.h
+++ b/src/include/gnunet_time_lib.h
@@ -314,6 +314,22 @@ struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_add (struct
                                                       GNUNET_TIME_Relative
                                                       duration);
 
+
+/**
+ * Subtract a given relative duration from the
+ * given start time.
+ *
+ * @param start some absolute time
+ * @param duration some relative time to subtract
+ * @return ZERO if start <= duration, or FOREVER if start time is FOREVER; start-duration otherwise
+ */
+struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_subtract (struct
+                                                           GNUNET_TIME_Absolute
+                                                           start,
+                                                           struct
+                                                           GNUNET_TIME_Relative
+                                                           duration);
+
 /**
  * Multiply relative time by a given factor.
  *