iMIP: Notification subjects and bodies omit the event start date, time and timezone for recurring events

CHANGELOG.md

@@ -13,6 +13,7 @@ If you are upgrading from v0.16.x, replace the binary (or run `docker pull`). If
 ## Fixed
 - WebDAV: `PROPFIND` responses do not declare the namespace of every requested property on the `DAV:multistatus` element.
 - MTA: SMTP session state obtained before `STARTTLS` is discarded once the TLS handshake completes, as required by RFC 3207.
+- iMIP: Notification subjects and bodies omit the event start date, time and timezone for recurring events.
 
 ## [0.16.21] - 2026-09-06
 

crates/services/src/task_manager/imip.rs

@@ -414,13 +414,13 @@ pub async fn build_itip_template(
         }
     };
 
-    let mut has_rrule = false;
-    let mut details = Vec::with_capacity(4);
+    let mut when_detail: Option<(usize, &ItipValue)> = None;
+    let mut details: Vec<AHashMap<CalendarTemplateVariable, String>> = Vec::with_capacity(4);
     for field in [
         ICalendarProperty::Summary,
         ICalendarProperty::Description,
-        ICalendarProperty::Rrule,
         ICalendarProperty::Dtstart,
+        ICalendarProperty::Rrule,
         ICalendarProperty::Location,
         ICalendarProperty::Conference,
     ] {
@@ -430,11 +430,7 @@ pub async fn build_itip_template(
             let field_name = match &field {
                 ICalendarProperty::Summary => locale.calendar_summary,
                 ICalendarProperty::Description => locale.calendar_description,
-                ICalendarProperty::Rrule => {
-                    has_rrule = true;
-                    locale.calendar_when
-                }
-                ICalendarProperty::Dtstart if !has_rrule => locale.calendar_when,
+                ICalendarProperty::Dtstart | ICalendarProperty::Rrule => locale.calendar_when,
                 ICalendarProperty::Location => locale.calendar_location,
                 ICalendarProperty::Conference => locale.calendar_conference,
                 _ => continue,
@@ -447,7 +443,11 @@ pub async fn build_itip_template(
                 ICalendarProperty::Summary => {
                     subject.push_str(&value);
                 }
-                ICalendarProperty::Dtstart | ICalendarProperty::Rrule => {
+                ICalendarProperty::Dtstart => {
+                    subject.push_str(" @ ");
+                    subject.push_str(&value);
+                }
+                ICalendarProperty::Rrule if when_detail.is_none() => {
                     subject.push_str(" @ ");
                     subject.push_str(&value);
                 }
@@ -468,6 +468,33 @@ pub async fn build_itip_template(
                 variables.insert_single(variable, value.clone());
             }
 
+            if matches!(field, ICalendarProperty::Rrule)
+                && let Some((index, start_value)) = when_detail
+                && let Some(detail) = details.get_mut(index)
+            {
+                if let Some(when_value) = detail.get_mut(&CalendarTemplateVariable::Value) {
+                    when_value.push_str(", ");
+                    when_value.push_str(&value);
+                }
+
+                if let Some(old_entry) = old_entry {
+                    detail.insert(
+                        CalendarTemplateVariable::Changed,
+                        locale.calendar_changed.to_string(),
+                    );
+                    let old_value = detail
+                        .entry(CalendarTemplateVariable::OldValue)
+                        .or_insert_with(|| {
+                            formatter.field_to_string(start_value, DateStyle::Short)
+                        });
+                    old_value.push_str(", ");
+                    old_value
+                        .push_str(&formatter.field_to_string(&old_entry.value, DateStyle::Short));
+                }
+
+                continue;
+            }
+
             let mut detail = AHashMap::with_capacity(4);
             detail.insert(CalendarTemplateVariable::Key, field_name.to_string());
             if matches!(field, ICalendarProperty::Conference)
@@ -486,6 +513,9 @@ pub async fn build_itip_template(
                     formatter.field_to_string(&old_entry.value, DateStyle::Short),
                 );
             }
+            if matches!(field, ICalendarProperty::Dtstart) && when_detail.is_none() {
+                when_detail = Some((details.len(), &entry.value));
+            }
             details.push(detail);
         }
     }

tests/src/webdav/cal_scheduling.rs

@@ -1038,6 +1038,17 @@ pub async fn test_build_itip_templates(test: &TestServer) {
                     tz_id: Tz::from_str("New Zealand").unwrap().as_id(),
                 }),
             },
+            ItipField {
+                name: ICalendarProperty::Rrule,
+                value: ItipValue::Rrule(Box::new(ICalendarRecurrenceRule {
+                    freq: ICalendarFrequency::Weekly,
+                    byday: vec![ICalendarDay {
+                        ordwk: None,
+                        weekday: ICalendarWeekday::Tuesday,
+                    }],
+                    ..Default::default()
+                })),
+            },
             ItipField {
                 name: ICalendarProperty::Attendee,
                 value: ItipValue::Participants(vec![
@@ -1170,6 +1181,17 @@ pub async fn test_build_itip_templates(test: &TestServer) {
                         tz_id: Tz::from_str("New Zealand").unwrap().as_id(),
                     }),
                 },
+                ItipField {
+                    name: ICalendarProperty::Rrule,
+                    value: ItipValue::Rrule(Box::new(ICalendarRecurrenceRule {
+                        freq: ICalendarFrequency::Weekly,
+                        byday: vec![ICalendarDay {
+                            ordwk: None,
+                            weekday: ICalendarWeekday::Tuesday,
+                        }],
+                        ..Default::default()
+                    })),
+                },
                 ItipField {
                     name: ICalendarProperty::Attendee,
                     value: ItipValue::Participants(vec![
@@ -1206,8 +1228,49 @@ pub async fn test_build_itip_templates(test: &TestServer) {
                         tz_id: Tz::from_str("New Zealand").unwrap().as_id(),
                     }),
                 },
+                ItipField {
+                    name: ICalendarProperty::Rrule,
+                    value: ItipValue::Rrule(Box::new(ICalendarRecurrenceRule {
+                        freq: ICalendarFrequency::Daily,
+                        ..Default::default()
+                    })),
+                },
             ],
         },
+        ItipSummary::Update {
+            method: ICalendarMethod::Request,
+            current: vec![
+                ItipField {
+                    name: ICalendarProperty::Summary,
+                    value: ItipValue::Text("Standup".to_string()),
+                },
+                ItipField {
+                    name: ICalendarProperty::Dtstart,
+                    value: ItipValue::Time(ItipTime {
+                        start: 1750616068,
+                        tz_id: Tz::from_str("New Zealand").unwrap().as_id(),
+                    }),
+                },
+                ItipField {
+                    name: ICalendarProperty::Rrule,
+                    value: ItipValue::Rrule(Box::new(ICalendarRecurrenceRule {
+                        freq: ICalendarFrequency::Weekly,
+                        byday: vec![ICalendarDay {
+                            ordwk: None,
+                            weekday: ICalendarWeekday::Tuesday,
+                        }],
+                        ..Default::default()
+                    })),
+                },
+            ],
+            previous: vec![ItipField {
+                name: ICalendarProperty::Rrule,
+                value: ItipValue::Rrule(Box::new(ICalendarRecurrenceRule {
+                    freq: ICalendarFrequency::Daily,
+                    ..Default::default()
+                })),
+            }],
+        },
     ]
     .into_iter()
     .enumerate()