diff --git a/src/NodaUncertaintyHelper.php b/src/NodaUncertaintyHelper.php
index 1c33a65..164618a 100644
--- a/src/NodaUncertaintyHelper.php
+++ b/src/NodaUncertaintyHelper.php
@@ -68,6 +68,20 @@ final class NodaUncertaintyHelper {
         "?",
     ];
 
+    /**
+     * Trims common characters and charater marks.
+     *
+     * @param string $input Input text.
+     *
+     * @return string
+     */
+    public static function trim(string $input):string {
+
+        $input = \trim($input, ", \t\n\r\n;-:");
+        return $input;
+
+    }
+
     /**
      * Removes uncertainty indicators from an time name.
      *
@@ -77,6 +91,8 @@ final class NodaUncertaintyHelper {
      */
     public static function cleanUncertaintyIndicatorsTime(string $name):string {
 
+        $name = self::trim($name);
+
         if (\in_array($name, self::TIME_INDICATORS_DISALLOWED, true)) {
             return "";
         }
@@ -84,18 +100,18 @@ final class NodaUncertaintyHelper {
         // Remove uncertainty prefixes
         foreach (NodaUncertaintyHelper::TIME_UNCERTAINTY_PREFIXES as $prefix) {
             if (\substr($name, 0, \strlen($prefix)) === "$prefix") {
-                $name = trim(substr($name, \strlen($prefix)));
+                $name = substr($name, \strlen($prefix));
             }
         }
 
         // Remove uncertainty sufixes
         foreach (NodaUncertaintyHelper::TIME_UNCERTAINTY_SUFFIXES as $suffix) {
             if (\substr($name, \strlen($suffix) * -1) === "$suffix") {
-                $name = \trim(\substr($name, 0, \strlen($suffix) * -1));
+                $name = \substr($name, 0, \strlen($suffix) * -1);
             }
         }
 
-        return \trim($name);
+        return self::trim($name);
 
     }
 
@@ -137,7 +153,7 @@ final class NodaUncertaintyHelper {
      */
     public static function cleanUncertaintyIndicatorsPlace(string $ort_name):string {
 
-        $ort_name = \trim($ort_name);
+        $ort_name = self::trim($ort_name);
 
         if (\in_array($ort_name, self::PLACE_INDICATORS_DISALLOWED, true)) {
             return "";
@@ -146,18 +162,18 @@ final class NodaUncertaintyHelper {
         // Remove uncertainty prefixes
         foreach (NodaUncertaintyHelper::PLACE_UNCERTAINTY_PREFIXES as $prefix) {
             if (\substr($ort_name, 0, \strlen($prefix)) === "$prefix") {
-                $ort_name = trim(substr($ort_name, \strlen($prefix)));
+                $ort_name = substr($ort_name, \strlen($prefix));
             }
         }
 
         // Remove uncertainty sufixes
         foreach (NodaUncertaintyHelper::PLACE_UNCERTAINTY_SUFFIXES as $suffix) {
             if (\substr($ort_name, \strlen($suffix) * -1) === "$suffix") {
-                $ort_name = \trim(\substr($ort_name, 0, \strlen($suffix) * -1));
+                $ort_name = \substr($ort_name, 0, \strlen($suffix) * -1);
             }
         }
 
-        return \trim($ort_name);
+        return self::trim($ort_name);
 
     }
 
@@ -199,7 +215,7 @@ final class NodaUncertaintyHelper {
      */
     public static function cleanUncertaintyIndicatorsPersinst(string $value):string {
 
-        $value = \trim($value);
+        $value = self::trim($value);
 
         if (\in_array($value, self::PERSINST_INDICATORS_DISALLOWED, true)) {
             return "";
@@ -217,7 +233,7 @@ final class NodaUncertaintyHelper {
             }
         }
 
-        return \trim($value);
+        return self::trim($value);
 
     }