My birthday was written in my personal contact in my Google address book. This also appears in the birthdays calendar on Android P as well as in the web version. As the anniversary no longer applies, I removed it from my contact. It no longer appears on the Google online calendar.
However, it continues to show in the Android version, also on the widget of my home screen. I've tried to allow the calendar application to refresh twice, I closed it via the launcher. It hurts every time I see it. Is there a way to delete this calendar entry?