diff --git a/app/Models/RecurringInvoice.php b/app/Models/RecurringInvoice.php
index 063cbe46daea..a650ba3c7ea4 100644
--- a/app/Models/RecurringInvoice.php
+++ b/app/Models/RecurringInvoice.php
@@ -16,6 +16,7 @@ use App\Helpers\Invoice\InvoiceSumInclusive;
 use App\Models\Filterable;
 use App\Utils\Traits\MakesDates;
 use App\Utils\Traits\MakesHash;
+use App\Utils\Traits\Recurring\HasRecurrence;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\SoftDeletes;
 use Illuminate\Support\Carbon;
@@ -29,6 +30,8 @@ class RecurringInvoice extends BaseModel
     use SoftDeletes;
     use Filterable;
     use MakesDates;
+    use HasRecurrence;
+
     /**
      * Invoice Statuses.
      */
@@ -387,7 +390,7 @@ class RecurringInvoice extends BaseModel
                 'due_date' => $next_due_date->format('Y-m-d'),
             ];
 
-            $next_send_date = $this->nextDateByFrequency($next_send_date);        
+            $next_send_date = $this->calculateDueDate($next_send_date);        
 
         }
 
@@ -404,20 +407,15 @@ class RecurringInvoice extends BaseModel
     }
 
 
-    private function calculateDueDate($terms, $date) 
+    private function calculateDueDate($date) 
     {
 
-        switch ($terms) {
-            case 'client_terms':
+        switch ($this->due_date_days) {
+            case 'terms':
                 return $this->calculateDateFromTerms($date);
                 break;
-            case 'first_of_month':
-                return $this->calculateFirstDayOfMonth($date);
-                break;
-            case 'last_of_month':
-                break;
             default:
-                return $this->setDayOfMonth($date, $terms);
+                return $this->setDayOfMonth($date, $this->due_date_days);
                 break;
         }
     }
diff --git a/app/Utils/Traits/Recurring/HasRecurrence.php b/app/Utils/Traits/Recurring/HasRecurrence.php
index 30f7d331a896..6560e18dd956 100644
--- a/app/Utils/Traits/Recurring/HasRecurrence.php
+++ b/app/Utils/Traits/Recurring/HasRecurrence.php
@@ -12,6 +12,7 @@
 namespace App\Utils\Traits\Recurring;
 
 use Illuminate\Support\Carbon;
+use Illuminate\Support\Facades\Log;
 
 trait HasRecurrence
 {
@@ -39,7 +40,7 @@ trait HasRecurrence
     public function calculateLastDayOfMonth($date)
     {
         if($date->isLastOfMonth())
-            return $date->copy()->endOfMonth()->addMonthNoOverflow();
+            return $date->copy()->addMonthNoOverflow()->endOfMonth();
 
         return $date->copy()->endOfMonth();
     }
@@ -50,13 +51,19 @@ trait HasRecurrence
      * @param Carbon $date              The start date
      * @param String|Int $day_of_month  The day of the month
      */
-    public function setDateOfMonth($date, $day_of_month)
+    public function setDayOfMonth($date, $day_of_month)
     {
 
         $set_date = $date->copy()->setUnitNoOverflow('day', $day_of_month, 'month');
 
-        if($set_date->isPast())
-            return $set_date->addMonthNoOverflow();
+        //If the set date is less than the original date we need to add a month.
+        //If we are overflowing dates, then we need to diff the dates and ensure it doesn't equal 0
+        if($set_date->lte($date) || $set_date->diffInDays($date) == 0)
+            $set_date->addMonthNoOverflow();
+
+        if($day_of_month == '31')
+            $set_date->endOfMonth();
+
 
         return $set_date;
     }
diff --git a/tests/Unit/RecurringDueDatesTest.php b/tests/Unit/RecurringDueDatesTest.php
index 6196f360b7e2..fa153791a076 100644
--- a/tests/Unit/RecurringDueDatesTest.php
+++ b/tests/Unit/RecurringDueDatesTest.php
@@ -24,10 +24,6 @@ class RecurringDueDatesTest extends TestCase
 
     use HasRecurrence;
 
-    public function setUp() :void
-    {
-
-    }
 
     public function testFirstDate()
     {
@@ -37,6 +33,143 @@ class RecurringDueDatesTest extends TestCase
         $due_date = $this->calculateFirstDayOfMonth($date);
 
         $this->assertEquals('2020-03-01', $due_date->format('Y-m-d'));
+    }
+
+    public function testFirstOfMonthOnFirst()
+    {
+
+        $date = Carbon::parse('2020-02-01');
+
+        $due_date = $this->calculateFirstDayOfMonth($date);
+
+        $this->assertEquals('2020-03-01', $due_date->format('Y-m-d'));
+
+    }  
+
+
+    public function testFirstOfMonthOnLast()
+    {
+
+        $date = Carbon::parse('2020-03-31');
+
+        $due_date = $this->calculateFirstDayOfMonth($date);
+
+        $this->assertEquals('2020-04-01', $due_date->format('Y-m-d'));
+        
+    }    
+
+    public function testLastOfMonth()
+    {
+
+        $date = Carbon::parse('2020-02-15');
+
+        $due_date = $this->calculateLastDayOfMonth($date);
+
+        $this->assertEquals('2020-02-29', $due_date->format('Y-m-d'));
+
+    } 
+
+    public function testLastOfMonthOnFirst()
+    {
+
+        $date = Carbon::parse('2020-02-1');
+
+        $due_date = $this->calculateLastDayOfMonth($date);
+
+        $this->assertEquals('2020-02-29', $due_date->format('Y-m-d'));
+
+    } 
+
+    public function testLastOfMonthOnLast()
+    {
+
+        $date = Carbon::parse('2020-02-29');
+
+        $due_date = $this->calculateLastDayOfMonth($date);
+
+        $this->assertEquals('2020-03-31', $due_date->format('Y-m-d'));
+
+    } 
+
+    public function testDayOfMonth()
+    {
+        $date = Carbon::parse('2020-02-01');
+
+        $due_date = $this->setDayOfMonth($date, '15');
+
+        $this->assertEquals('2020-02-15', $due_date->format('Y-m-d'));
 
     }
+
+    public function testDayOfMonthInFuture()
+    {
+        $date = Carbon::parse('2020-02-16');
+
+        $due_date = $this->setDayOfMonth($date, '15');
+
+        $this->assertEquals('2020-03-15', $due_date->format('Y-m-d'));
+
+    }
+
+    public function testDayOfMonthSameDay()
+    {
+        $date = Carbon::parse('2020-02-01');
+
+        $due_date = $this->setDayOfMonth($date, '1');
+
+        $this->assertEquals('2020-03-01', $due_date->format('Y-m-d'));
+
+    }
+
+
+    public function testDayOfMonthWithOverflow()
+    {
+        $date = Carbon::parse('2020-1-31');
+
+        $due_date = $this->setDayOfMonth($date, '31');
+
+        $this->assertEquals('2020-02-29', $due_date->format('Y-m-d'));
+
+    }
+
+    public function testDayOfMonthWithOverflow2()
+    {
+        $date = Carbon::parse('2020-02-29');
+
+        $due_date = $this->setDayOfMonth($date, '31');
+
+        $this->assertEquals('2020-03-31', $due_date->format('Y-m-d'));
+
+    }
+
+    public function testDayOfMonthWithOverflow3()
+    {
+        $date = Carbon::parse('2020-01-30');
+
+        $due_date = $this->setDayOfMonth($date, '30');
+
+        $this->assertEquals('2020-02-29', $due_date->format('Y-m-d'));
+
+    }
+
+    public function testDayOfMonthWithOverflow4()
+    {
+        $date = Carbon::parse('2019-02-28');
+
+        $due_date = $this->setDayOfMonth($date, '31');
+
+        $this->assertEquals('2019-03-31', $due_date->format('Y-m-d'));
+
+    }
+
+    public function testDayOfMonthWithOverflow5()
+    {
+        $date = Carbon::parse('2019-1-31');
+
+        $due_date = $this->setDayOfMonth($date, '31');
+
+        $this->assertEquals('2019-02-28', $due_date->format('Y-m-d'));
+
+    }
+
 }