monthHeadingFormat not working

[csikoszoltan]

Hello! Im trying to set up a different format (yyyy MMMM) for the month view, but nothing is working. Locale is hu. My current code is the following:

<datepicker
    id="document_date"
    v-model="form.document_date"
    :monthHeadingFormat="'yyyy MMMM'"
    :startingView="'year'"
    :locale="locale"
/>

Anyone knows what should I do to change it to year-month format?

Thanks!