💄show duration in event list display

src/booking.py

@@ -151,7 +151,8 @@ class Calendar(models.Model):
 
 @app.admin(ordering=("start", "end", "calendar", "name"),
            list_filter=("cancelled",),
-           list_display=("name", "calendar", "created", "start", "end"))
+           list_display=("name", "calendar", "created", "duration", "start",
+                         "end"))
 class Event(models.Model):
     """
     Event model to store events in a calendar and send them to a CalDAV server.
@@ -242,6 +243,14 @@ class Event(models.Model):
     def uuid(self) -> UUID:
         return shortuuid.decode(self.id.__str__())
 
+    def duration(self) -> str:
+        """
+        Calculate the duration of the event.
+        :return: The duration in minutes.
+        """
+        duration = (self.end - self.start).total_seconds() // 60
+        return f"{duration:.0f}m"
+
     def __str__(self):
         return self.name