diff --git a/app/Support/Navigation.php b/app/Support/Navigation.php
index 1018b784e0..fe83828573 100644
--- a/app/Support/Navigation.php
+++ b/app/Support/Navigation.php
@@ -232,7 +232,7 @@ class Navigation
             return $date;
         }
         if ($repeatFreq === 'custom') {
-            return $theDate; // the date is already at the start.
+            return $date; // the date is already at the start.
         }
 
 
@@ -283,6 +283,18 @@ class Navigation
 
             return $date;
         }
+        // a custom range requires the session start
+        // and session end to calculate the difference in days.
+        // this is then subtracted from $theDate (* $subtract).
+        if($repeatFreq === 'custom') {
+            /** @var Carbon $tStart */
+            $tStart = session('start', Carbon::now()->startOfMonth());
+            /** @var Carbon $tEnd */
+            $tEnd       = session('end', Carbon::now()->endOfMonth());
+            $diffInDays = $tStart->diffInDays($tEnd);
+            $date->subDays($diffInDays * $subtract);
+            return $date;
+        }
 
         throw new FireflyException('Cannot do subtractPeriod for $repeat_freq "' . $repeatFreq . '"');
     }