diff --git a/src/NodaTimeSplitter.php b/src/NodaTimeSplitter.php
index be754b5..960c44a 100644
--- a/src/NodaTimeSplitter.php
+++ b/src/NodaTimeSplitter.php
@@ -845,7 +845,7 @@ final class NodaTimeSplitter {
             }
         }
 
-        if (\preg_match("/^(Ab|Seit|seit)\ /", $datum)) {
+        if (\preg_match("/^(Ab|ab|Seit|seit)\ /", $datum)) {
             if (($spacePos = \strpos($datum, " ")) === false) {
                 return [];
             }
diff --git a/src/NodaUncertaintyHelper.php b/src/NodaUncertaintyHelper.php
index d35a274..ddf9325 100644
--- a/src/NodaUncertaintyHelper.php
+++ b/src/NodaUncertaintyHelper.php
@@ -80,6 +80,7 @@ final class NodaUncertaintyHelper {
         "circa ",
         "gegen ",
         "um ",
+        "Um ",
         "verm. ",
         "Verm. ",
         "vermtl. ",
@@ -103,6 +104,7 @@ final class NodaUncertaintyHelper {
         " (vermutl.)",
         " körül",
         ", um",
+        " (um)",
     ];
 
     /**