Unfortunately this nicely phrased sentence on the start-page does not always work. So I had to remove the word in

lektor/docker/Dockerfile

@@ -8,7 +8,7 @@ RUN sed -i '/de_DE.UTF-8/s/^# //g' /etc/locale.gen && locale-gen
 
 RUN python3 -m venv /opt/venv
 
-RUN . /opt/venv/bin/activate && pip install ics requests bs4
+RUN . /opt/venv/bin/activate && pip install requests bs4 recurring_ical_events icalendar
 
 COPY entrypoint.sh /opt/entrypoint.sh
 RUN chmod +x /opt/entrypoint.sh

lektor/lektordata/scripts/calendar-fetcher-main.py

@@ -1,8 +1,9 @@
 from bs4 import BeautifulSoup
 import sys
+from datetime import datetime, date
+import recurring_ical_events
 import requests
-from ics import Calendar
-import arrow
+from icalendar import Calendar
 import locale
 
 
@@ -32,21 +33,41 @@ with open(sourcefile, 'r') as file:
 
 url = sys.argv[1]
 
+locale.setlocale(locale.LC_TIME, 'de_DE.UTF-8')
+
 #TODO: Handling HTTP request or pasring errors is currently completely missing (although I implemented such a nice handling if the script would just gracefully continue on exceptions)
-c = Calendar(requests.get(url).text)
+response = requests.get(url)
+calendar = Calendar.from_ical(response.content)
 
-locale.setlocale(locale.LC_TIME, locale.normalize("de_DE.UTF-8"))
+# Get recurring and non-recurring events
+events = recurring_ical_events.of(calendar).after(datetime.now())
 
-colevents = list(c.timeline.start_after(arrow.now()))
+try:
+    event = next(events)
 
-if len(colevents) > 0 :
-    weekday = colevents[0].begin.strftime("%A")
-    date = colevents[0].begin.strftime("%-d. %B")
-    time = colevents[0].begin.strftime(" %-H:%M") if not colevents[0].all_day else ""
-    name = colevents[0].name
-    location = " in " + colevents[0].location if colevents[0].location != None else ""
-    replacestr = "<div class=\"nextevent\">{} <strong> {}{}, {}</strong>{}</div>".format(weekday, date, time, name, location)
+
+    start = event.get('dtstart').dt
+    out_summary = event.get('summary')
+    location = event.get('location', 'No location specified')
+    
+    out_weekday = start.strftime("%A")
+    out_startdate = start.strftime("%-d. %B")
+
+    # Format output based on whether it's an all-day event
+    if isinstance(start, date) and not isinstance(start, datetime):
+        out_starttime = ""
     else:
+        out_starttime = start.strftime(" %-H:%M")
+        
+    if location != 'No location specified':
+        out_location = f", {location}"
+    else:
+        out_location = ""
+
+    replacestr = "<div class=\"nextevent\">{} <strong> {}{}, {}</strong>{}</div>".format(out_weekday, out_startdate, out_starttime, out_summary, out_location)
+
+except StopIteration:
+
     replacestr = fallbackreplacestr
 
 # Why should we check if sourcestring is in the file when it originates from there?!?
@@ -55,6 +76,7 @@ else:
 # Also an empty string is a perfect match and matches in the wrong place, therefore we check for a minimal length > 0
 # TODO: Most probably replacement could be done by BeautifulSoup too.
 # But as this is a collection of StackOverflow roadkill rather than fine crafted menu of purest python ingredients, that's just what I could catch most easily.
+
 if len(sourcestr) > 0 and sourcestr in file_contents:
     
     updated_contents = file_contents.replace(sourcestr, replacestr)

lektor/lektordata/scripts/calendar-fetcher.py

@@ -1,17 +1,49 @@
-import sys
+from datetime import datetime, date
+import recurring_ical_events
 import requests
-from ics import Calendar
-import arrow
+from icalendar import Calendar
 import locale
+import sys
 
-if len(sys.argv) != 2:
-	print("Usage: python3 {} <ICS_URL>".format(sys.argv[0]))
+def fetch_upcoming_events(ics_url):
+    # Set German locale
+    locale.setlocale(locale.LC_TIME, 'de_DE.UTF-8')
     
-url = sys.argv[1]
+    response = requests.get(ics_url)
+    calendar = Calendar.from_ical(response.content)
     
-c = Calendar(requests.get(url).text)
+    # Get recurring and non-recurring events
+    events = recurring_ical_events.of(calendar).after(datetime.now())
     
-locale.setlocale(locale.LC_TIME, locale.normalize("de_DE.UTF-8"))
+    for event in events:
+        start = event.get('dtstart').dt
+        out_summary = event.get('summary')
+        location = event.get('location', 'No location specified')
+        
+        out_startdate = start.strftime("%a. %-d. %B %Y")
+
+        # Format output based on whether it's an all-day event
+        if isinstance(start, date) and not isinstance(start, datetime):
+            out_starttime = "&nbsp;"
+        else:
+            out_starttime = start.strftime('%-H:%M')
+            
+        if location != 'No location specified':
+            out_location = location
+        else:
+            out_location = "&nbsp;"
+
+        print(f"* <div>{out_summary}</div>&nbsp;")
+        print(f"  * <div>{out_startdate}</div>&nbsp;")
+        print(f"  * <div>{out_starttime}</div>&nbsp;")
+        print(f"  * <div>{out_location}</div>&nbsp;")
+
+
+if __name__ == "__main__":
+
+    ics_url = sys.argv[1]
+
+    # ics_url = "https://backoffice.pc-stammertal.ch/remote.php/dav/public-calendars/RqLX5wj25aY6cpnP?export"
 
     print("_model: page")
     print("---")
@@ -19,11 +51,7 @@ print("title: Termine")
     print("---")
     print("body:")
     print("")
-for event in list(c.timeline.start_after(arrow.now())):
-	print("* <div>{}</div>&nbsp;".format(event.name))
-	print("  * <div>{}</div>&nbsp;".format(event.begin.strftime("%a. %-d. %B %Y")))
-	print("  * <div>{}</div>&nbsp;".format(event.begin.strftime("%-H:%M") if not event.all_day else "&nbsp;"))
-	print("  * <div>{}</div>&nbsp;".format(event.location if event.location != None else "&nbsp;"))
+    fetch_upcoming_events(ics_url)
     print("")
     print("---")
     print("_template: page.html")