diff --git a/4/calendar.ics b/4/calendar.ics
index 95e8868..5c57a90 100644
--- a/4/calendar.ics
+++ b/4/calendar.ics
@@ -13,9 +13,9 @@ LOCATION:http://bbb.liquidsoap.info/
 SUMMARY:Liquidshop: {{talk.firstname}} {{talk.lastname}} / {{talk.title}}
 DESCRIPTION:{{ talk.abstract | strip_newlines }}
 CLASS:PUBLIC
-DTSTART;TZID=GMT:20240527T{{talk.time | replace: ":",""}}
-DTEND;TZID=GMT-1:20240527T{{talk.time | replace: ":",""}}
-DTSTAMP;TZID=GMT:20240527T{{talk.time | replace: ":",""}}
-SEQUENCE:1
+DTSTART:20240527T{{talk.time | replace: ":",""}}
+DTEND:20240527T{{talk.time | replace: ":",""}}-0100
+DTSTAMP:20240527T{{talk.time | replace: ":",""}}
+SEQUENCE:0
 END:VEVENT
 {% endfor %}END:VCALENDAR