Date picker can't select "Today" button with specify language

Hi,
I have the UI is auto-generate via module

<report key="key" name="name" class="...">
    <description>description</description>
    <resource type="velocity" name="view" location="reportingplugin.vm"/>
    <resource type="velocity" name="excel" location="reportingplugin-excel.vm"/>
    <label>Report</label>
    <properties>
      <property>
        <key>filterid</key>
        <name>Filter</name>
        <type>filterpicker</type>
      </property>
      <property>
        <key>startDate</key>
        <name>Starting Date</name>
        <description>Starting date of the statistic</description>
        <type>date</type>
      </property>
      <property>
        <key>endDate</key>
        <name>Ending Date</name>
        <description>Ending date of the statistic</description>
        <type>date</type>
      </property>
  </properties>
</report>

Something like this:

When I click on date-picker → click today button → it works well

But the error happens when I change my profile language to Deutsch (Deutschland)

Does anyone have any idea about this?

Thank you so much.