diff --git a/libs/temporal/temporal/range.h b/libs/temporal/temporal/range.h
index d9873ccc9a..fe76d1716a 100644
--- a/libs/temporal/temporal/range.h
+++ b/libs/temporal/temporal/range.h
@@ -152,7 +152,12 @@ class LIBTEMPORAL_API Range {
 	Range (timepos_t const & s, timepos_t const & e) : _start (s), _end (e) {}
 	Range (samplepos_t const s, samplepos_t const e) : _start (s), _end (e) {}
 	bool empty() const { return _start == _end; }
-	timecnt_t length() const { return _start.distance (_end); }
+
+	/* length semantics: start + length = end thus end - start aka * start.distance (end)
+	 * extent semantics: 1 + (end - start)
+	 */
+
+	timecnt_t extent() const { return _start.distance (_end).increment(); }
 
 	RangeList subtract (RangeList &) const;
 
diff --git a/libs/temporal/temporal/timeline.h b/libs/temporal/temporal/timeline.h
index 8b8feb7e55..1e629701bc 100644
--- a/libs/temporal/temporal/timeline.h
+++ b/libs/temporal/temporal/timeline.h
@@ -370,6 +370,7 @@ class LIBTEMPORAL_API timecnt_t {
 	timecnt_t & operator+= (timecnt_t const & t);
 
 	timecnt_t decrement () const { return timecnt_t (_distance - 1, _position); }
+	timecnt_t increment () const { return timecnt_t (_distance + 1, _position); }
 
 	//timecnt_t operator- (timepos_t const & t) const;
 	//timecnt_t operator+ (timepos_t const & t) const;