diff --git a/duration/operation.go b/duration/operation.go
index 76f16e2..261d3e5 100644
--- a/duration/operation.go
+++ b/duration/operation.go
@@ -49,6 +49,14 @@ func (d Duration) RangeTo(dur Duration, rateP, rateI, rateD float64) []Duration
 		r = append(make([]Duration, 0), d, dur)
 	}
 
+	if r[0] > d {
+		r = append(append(make([]Duration, 0), d), r...)
+	}
+
+	if r[len(r)-1] < dur {
+		r = append(r, dur)
+	}
+
 	return r
 }
 
@@ -70,6 +78,14 @@ func (d Duration) RangeFrom(dur Duration, rateP, rateI, rateD float64) []Duratio
 		r = append(make([]Duration, 0), d, dur)
 	}
 
+	if r[0] > dur {
+		r = append(append(make([]Duration, 0), dur), r...)
+	}
+
+	if r[len(r)-1] < d {
+		r = append(r, d)
+	}
+
 	return r
 }