Apply suggestion from code review

Author: BurntimeX

wcfsetup/install/files/lib/system/gridView/filter/DateFilter.class.php

@@ -53,7 +53,7 @@ public function renderValue(string $value): string
         $locale = WCF::getLanguage()->getLocale();
         $fromString = $toString = '';
         if ($values[0] !== '') {
-            $fromDateTime = \DateTime::createFromFormat(
+            $fromDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d',
                 $values[0],
                 WCF::getUser()->getTimeZone()
@@ -70,7 +70,7 @@ public function renderValue(string $value): string
             }
         }
         if ($values[1] !== '') {
-            $toDateTime = \DateTime::createFromFormat(
+            $toDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d',
                 $values[1],
                 WCF::getUser()->getTimeZone()
@@ -108,21 +108,21 @@ private function getTimestamps(string $value): array
 
         $values = explode(';', $value);
         if (\count($values) === 2) {
-            $fromDateTime = \DateTime::createFromFormat(
+            $fromDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d',
                 $values[0]
             );
             if ($fromDateTime !== false) {
-                $fromDateTime->setTime(0, 0);
+                $fromDateTime = $fromDateTime->setTime(0, 0);
                 $from = $fromDateTime->getTimestamp();
             }
 
-            $toDateTime = \DateTime::createFromFormat(
+            $toDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d',
                 $values[1]
             );
             if ($toDateTime !== false) {
-                $toDateTime->setTime(23, 59, 59);
+                $toDateTime = $toDateTime->setTime(23, 59, 59);
                 $to = $toDateTime->getTimestamp();
             }
         }

wcfsetup/install/files/lib/system/gridView/filter/TimeFilter.class.php

@@ -55,7 +55,7 @@ public function renderValue(string $value): string
         $locale = WCF::getLanguage()->getLocale();
         $fromString = $toString = '';
         if ($values[0] !== '') {
-            $fromDateTime = \DateTime::createFromFormat(
+            $fromDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d\TH:i:sP',
                 $values[0],
                 WCF::getUser()->getTimeZone()
@@ -72,7 +72,7 @@ public function renderValue(string $value): string
             }
         }
         if ($values[1] !== '') {
-            $toDateTime = \DateTime::createFromFormat(
+            $toDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d\TH:i:sP',
                 $values[1],
                 WCF::getUser()->getTimeZone()
@@ -122,7 +122,7 @@ private function getTimestamps(string $value): array
 
     private function getTimestamp(string $date): int
     {
-        $dateTime = \DateTime::createFromFormat(
+        $dateTime = \DateTimeImmutable::createFromFormat(
             'Y-m-d\TH:i:sP',
             $date
         );

wcfsetup/install/files/lib/system/listView/filter/DateFilter.class.php

@@ -53,7 +53,7 @@ public function renderValue(string $value): string
         $locale = WCF::getLanguage()->getLocale();
         $fromString = $toString = '';
         if ($values[0] !== '') {
-            $fromDateTime = \DateTime::createFromFormat(
+            $fromDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d',
                 $values[0],
                 WCF::getUser()->getTimeZone()
@@ -70,7 +70,7 @@ public function renderValue(string $value): string
             }
         }
         if ($values[1] !== '') {
-            $toDateTime = \DateTime::createFromFormat(
+            $toDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d',
                 $values[1],
                 WCF::getUser()->getTimeZone()
@@ -108,21 +108,21 @@ private function getTimestamps(string $value): array
 
         $values = explode(';', $value);
         if (\count($values) === 2) {
-            $fromDateTime = \DateTime::createFromFormat(
+            $fromDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d',
                 $values[0]
             );
             if ($fromDateTime !== false) {
-                $fromDateTime->setTime(0, 0);
+                $fromDateTime = $fromDateTime->setTime(0, 0);
                 $from = $fromDateTime->getTimestamp();
             }
 
-            $toDateTime = \DateTime::createFromFormat(
+            $toDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d',
                 $values[1]
             );
             if ($toDateTime !== false) {
-                $toDateTime->setTime(23, 59, 59);
+                $toDateTime = $toDateTime->setTime(23, 59, 59);
                 $to = $toDateTime->getTimestamp();
             }
         }

wcfsetup/install/files/lib/system/listView/filter/TimeFilter.class.php

@@ -55,7 +55,7 @@ public function renderValue(string $value): string
         $locale = WCF::getLanguage()->getLocale();
         $fromString = $toString = '';
         if ($values[0] !== '') {
-            $fromDateTime = \DateTime::createFromFormat(
+            $fromDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d\TH:i:sP',
                 $values[0],
                 WCF::getUser()->getTimeZone()
@@ -72,7 +72,7 @@ public function renderValue(string $value): string
             }
         }
         if ($values[1] !== '') {
-            $toDateTime = \DateTime::createFromFormat(
+            $toDateTime = \DateTimeImmutable::createFromFormat(
                 'Y-m-d\TH:i:sP',
                 $values[1],
                 WCF::getUser()->getTimeZone()
@@ -122,7 +122,7 @@ private function getTimestamps(string $value): array
 
     private function getTimestamp(string $date): int
     {
-        $dateTime = \DateTime::createFromFormat(
+        $dateTime = \DateTimeImmutable::createFromFormat(
             'Y-m-d\TH:i:sP',
             $date
         );