diff --git a/workflow/engine/src/ProcessMaker/BusinessModel/Calendar.php b/workflow/engine/src/ProcessMaker/BusinessModel/Calendar.php
index 83ff11b05..9a9814125 100644
--- a/workflow/engine/src/ProcessMaker/BusinessModel/Calendar.php
+++ b/workflow/engine/src/ProcessMaker/BusinessModel/Calendar.php
@@ -19,8 +19,8 @@ class Calendar
 
     private $arrayWorkHourFieldDefinition = array(
         "DAY"        => array("type" => "int",  "required" => true, "empty" => false, "defaultValues" => array(0, 1, 2, 3, 4, 5, 6, 7), "fieldNameAux" => "day"),
-        "HOUR_START" => array("type" => "hour", "required" => true, "empty" => false, "defaultValues" => array(), "fieldNameAux" => "hourStart"),
-        "HOUR_END"   => array("type" => "hour", "required" => true, "empty" => false, "defaultValues" => array(), "fieldNameAux" => "hourEnd")
+        'HOUR_START' => array('type' => 'hour', 'required' => true, 'empty' => false, 'defaultValues' => array(), 'fieldNameAux' => 'hourStart', 'regexp' => '/^(?:[0-1]\d|2[0-3])\:[0-5]\d$/'),
+        'HOUR_END'   => array('type' => 'hour', 'required' => true, 'empty' => false, 'defaultValues' => array(), 'fieldNameAux' => 'hourEnd', 'regexp' => '/^(?:[0-1]\d|2[0-3])\:[0-5]\d$/')
     );
 
     private $arrayHolidayFieldDefinition = array(
@@ -751,4 +751,3 @@ class Calendar
         }
     }
 }
-
diff --git a/workflow/engine/src/ProcessMaker/BusinessModel/Process.php b/workflow/engine/src/ProcessMaker/BusinessModel/Process.php
index c8f2ea000..975013407 100644
--- a/workflow/engine/src/ProcessMaker/BusinessModel/Process.php
+++ b/workflow/engine/src/ProcessMaker/BusinessModel/Process.php
@@ -228,7 +228,13 @@ class Process
                                         }
                                         break;
                                     case "hour":
-                                        if (!preg_match('/^' . $regexpTime . '$/', $fieldValue)) {
+                                        $regexpTime = '/^' . $regexpTime . '$/';
+
+                                        if (array_key_exists('regexp', $arrayFieldDefinition[$fieldName])) {
+                                            $regexpTime = $arrayFieldDefinition[$fieldName]['regexp'];
+                                        }
+
+                                        if (!preg_match($regexpTime, $fieldValue)) {
                                             throw new \Exception(\G::LoadTranslation('ID_INVALID_VALUE', [$fieldNameAux]));
                                         }
                                         break;
@@ -532,16 +538,16 @@ class Process
             $trigger = new \ProcessMaker\BusinessModel\Trigger();
 
             /**
-             * Try catch block is added to escape the exception and continue editing 
-             * the properties of the process, otherwise there is no way to edit 
-             * the properties that the exception is thrown: trigger nonexistent. 
+             * Try catch block is added to escape the exception and continue editing
+             * the properties of the process, otherwise there is no way to edit
+             * the properties that the exception is thrown: trigger nonexistent.
              * The same goes for the similar blocks.
              */
             if (isset($arrayData["PRO_TRI_DELETED"]) && $arrayData["PRO_TRI_DELETED"] . "" != "") {
                 try {
                     $trigger->throwExceptionIfNotExistsTrigger($arrayData["PRO_TRI_DELETED"], $processUid, $this->arrayFieldNameForException["processTriDeleted"]);
                 } catch (\Exception $e) {
-                    
+
                 }
             }
 
@@ -549,7 +555,7 @@ class Process
                 try {
                     $trigger->throwExceptionIfNotExistsTrigger($arrayData["PRO_TRI_CANCELED"], $processUid, $this->arrayFieldNameForException["processTriCanceled"]);
                 } catch (\Exception $e) {
-                    
+
                 }
             }
 
@@ -557,7 +563,7 @@ class Process
                 try {
                     $trigger->throwExceptionIfNotExistsTrigger($arrayData["PRO_TRI_PAUSED"], $processUid, $this->arrayFieldNameForException["processTriPaused"]);
                 } catch (\Exception $e) {
-                    
+
                 }
             }
 
@@ -565,7 +571,7 @@ class Process
                 try {
                     $trigger->throwExceptionIfNotExistsTrigger($arrayData["PRO_TRI_REASSIGNED"], $processUid, $this->arrayFieldNameForException["processTriReassigned"]);
                 } catch (\Exception $e) {
-                    
+
                 }
             }
 
@@ -1834,4 +1840,3 @@ class Process
     }
 
 }
-