fix(datepicker): min-date: timezone fix for literals tweaks

* whitespace fixes
* set isNaN date on bad values like current codebase

src/datepicker/datepicker.js

@@ -630,10 +630,10 @@ function(scope, element, attrs, $compile, $parse, $document, $rootScope, $positi
           scope.watchData[key] = value;
           if (key === 'minDate' || key === 'maxDate') {
             var date = parseDate(value);
-            if(!date) {
-              var tryDate = new Date(value);
-              if(angular.isDate(tryDate) && !isNaN(tryDate)) {
-                dateArray = tryDate.toISOString().split('T')[0].split('-');
+            if (!date) {
+              date = new Date(value);
+              if (angular.isDate(date) && !isNaN(date)) {
+                var dateArray = date.toISOString().split('T')[0].split('-');
                 date = new Date(+dateArray[0], +dateArray[1] - 1, +dateArray[2]);
               }
             }