WordPress-Datenbank-Fehler: [Incorrect DATE value: '']
SELECT `dstart` FROM `mmwp_mec_dates` WHERE `post_id`='11' AND ((`dstart`='') OR (`dstart`<'' AND `dend`>='')) ORDER BY `dstart` DESC LIMIT 1

BEGIN:VCALENDAR VERSION:2.0 METHOD:PUBLISH CALSCALE:GREGORIAN PRODID:-//WordPress - MECv5.16.6.1711727817//EN X-ORIGINAL-URL:https://www.materiamedica.de/ BEGIN:VEVENT UID:MEC-6512bd43d9caa6e02c990b0a82652dca@materiamedica.de DTSTART:20240427T060000Z DTEND:20240427T160000Z DTSTAMP:20200625T150300Z RRULE:FREQ=MONTHLY CREATED:20200625 LAST-MODIFIED:20200625 SUMMARY:Monthly on 27th DESCRIPTION: URL:https://www.materiamedica.de/events/monthly-on-27th/ ORGANIZER;CN=:MAILTO: END:VEVENT END:VCALENDAR