diff --git a/app/cdash/include/dailyupdates.php b/app/cdash/include/dailyupdates.php
index 277c77219..ce474f63d 100644
--- a/app/cdash/include/dailyupdates.php
+++ b/app/cdash/include/dailyupdates.php
@@ -1108,14 +1108,13 @@ function addDailyChanges(int $projectid): void
         ', [$projectid, $date]);
 
         // Clean the backup directories.
-        $timeframe = config('cdash.backup_timeframe');
+        $deletion_time_threshold = time() - (int) config('cdash.backup_timeframe') * 3600;
         $dirs_to_clean = ['parsed', 'failed', 'inprogress'];
         foreach ($dirs_to_clean as $dir_to_clean) {
             $files = Storage::allFiles($dir_to_clean);
-            foreach ($files as $filename) {
-                $filepath = Storage::path($filename);
-                if (file_exists($filepath) && is_file($filepath) && time() - filemtime($filepath) > $timeframe * 3600) {
-                    Storage::delete($filepath);
+            foreach ($files as $file) {
+                if (Storage::lastModified($file) < $deletion_time_threshold) {
+                    Storage::delete($file);
                 }
             }
         }
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index a32ba3a2a..581e36861 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -14012,11 +14012,6 @@ parameters:
 			count: 3
 			path: app/cdash/include/dailyupdates.php
 
-		-
-			message: "#^Binary operation \"\\*\" between mixed and 3600 results in an error\\.$#"
-			count: 1
-			path: app/cdash/include/dailyupdates.php
-
 		-
 			message: """
 				#^Call to deprecated function add_last_sql_error\\(\\)\\:
@@ -14092,6 +14087,11 @@ parameters:
 			count: 1
 			path: app/cdash/include/dailyupdates.php
 
+		-
+			message: "#^Cannot cast mixed to int\\.$#"
+			count: 1
+			path: app/cdash/include/dailyupdates.php
+
 		-
 			message: "#^Construct empty\\(\\) is not allowed\\. Use more strict comparison\\.$#"
 			count: 5
@@ -14312,11 +14312,6 @@ parameters:
 			count: 2
 			path: app/cdash/include/dailyupdates.php
 
-		-
-			message: "#^Only numeric types are allowed in \\-, int\\|false given on the right side\\.$#"
-			count: 1
-			path: app/cdash/include/dailyupdates.php
-
 		-
 			message: "#^Parameter \\#1 \\$datetime of function strtotime expects string, string\\|null given\\.$#"
 			count: 1