Fix timezone issues when using rrule

ical.js

@@ -610,7 +610,12 @@ module.exports = {
               // If the original date has a TZID, add it
               if (curr.start.tz) {
                 const tz = getTimeZone(curr.start.tz);
-                rule += `;DTSTART;TZID=${tz}:${curr.start.toISOString().replace(/[-:]/g, '')}`;
+                // If a timezone is provided, rrule requires the time to be local
+                const adjustedTimeString = curr.start
+                  .toLocaleString('sv', {timeZone: tz})
+                  .replace(/ /g, 'T')
+                  .replace(/[-:]/g, '');
+                rule += `;DTSTART;TZID=${tz}:${adjustedTimeString}`;
               } else {
                 rule += `;DTSTART=${curr.start.toISOString().replace(/[-:]/g, '')}`;
               }

test/test.js

@@ -11,6 +11,10 @@ const _ = require('underscore');
 const moment = require('moment-timezone');
 const ical = require('../node-ical.js');
 
+process.on('uncaughtException', error => {
+  console.log('Caught exception: ' + error.stack);
+});
+
 vows
   .describe('node-ical')
   .addBatch({
@@ -150,8 +154,10 @@ vows
           });
         },
         'tzid offset correctly applied'(event) {
-          const start = new Date('2002-10-28T22:00:00.000Z');
-          assert.equal(event.start.valueOf(), start.valueOf());
+          assert.ok(moment.tz.zone(event.start.tz), 'zone does not exist');
+          const ref = '2002-10-28T22:00:00Z';
+          const start = moment(event.start).tz(event.start.tz);
+          assert.equal(start.utc().format(), ref);
         }
       }
     },
@@ -1051,6 +1057,84 @@ vows
           assert.equal(task.summary, 'test export import');
         }
       }
+    },
+    'with test22.ics (testing dtstart of rrule with timezones)': {
+      topic() {
+        return ical.parseFile('./test/test22.ics');
+      },
+      'first event': {
+        topic(events) {
+          return _.select(_.values(events), x => {
+            return x.uid === '000021a';
+          })[0];
+        },
+        'datetype is date-time'(topic) {
+          assert.equal(topic.datetype, 'date-time');
+        },
+        'has GMT+1 timezone'(topic) {
+          assert.equal(topic.start.tz, 'Europe/Berlin');
+        },
+        'starts 14 Jul 2022 @ 12:00:00 (UTC)'(topic) {
+          assert.equal(topic.start.toISOString(), '2022-07-14T12:00:00.000Z');
+        }
+      },
+      'recurring yearly frist event (14 july)': {
+        topic(events) {
+          const ev = _.select(_.values(events), x => {
+            return x.uid === '000021a';
+          })[0];
+          return ev.rrule.between(new Date(2023, 0, 1), new Date(2024, 0, 1))[0];
+        },
+        'dt start well set'(topic) {
+          assert.equal(topic.toDateString(), new Date(2023, 6, 14).toDateString());
+        },
+        'starts 14 Jul 2023 @ 12:00:00 (UTC)'(topic) {
+          assert.equal(topic.toISOString(), '2023-07-14T12:00:00.000Z');
+        }
+      },
+      'second event': {
+        topic(events) {
+          return _.select(_.values(events), x => {
+            return x.uid === '000021b';
+          })[0];
+        },
+        'datetype is date-time'(event) {
+          assert.equal(event.datetype, 'date-time');
+        },
+        'start date': {
+          topic(event) {
+            return event.start;
+          },
+          'has correct timezone'(start) {
+            assert.equal(start.tz, 'Etc/GMT-2');
+          },
+          'starts 15 Jul 2022 @ 12:00:00 (UTC)'(start) {
+            assert.equal(start.toISOString(), '2022-07-15T12:00:00.000Z');
+          }
+        },
+        'has recurrences': {
+          topic(event) {
+            return event.rrule;
+          },
+          'that are defined'(rrule) {
+            assert.ok(rrule, 'no rrule defined');
+          },
+          'that have timezone info'(rrule) {
+            assert.ok(rrule.options.tzid, 'no tzid property on rrule');
+          },
+          'that keep correct timezone info in recurrences'(rrule) {
+            assert.equal(rrule.options.tzid, 'Etc/GMT-2');
+          }
+        },
+        'has a first recurrence': {
+          topic(event) {
+            return event.rrule.between(new Date(2023, 0, 1), new Date(2024, 0, 1))[0];
+          },
+          'that starts 15 Jul 2023 @ 12:00:00 (UTC)'(rc) {
+            assert.equal(rc.toISOString(), '2023-07-15T12:00:00.000Z');
+          }
+        }
+      }
     }
   })
   .export(module);

test/test21-mod.ics

@@ -0,0 +1,21 @@
+BEGIN:VCALENDAR
+BEGIN:VEVENT
+TRANSP:OPAQUE
+X-MICROSOFT-CDO-INTENDEDSTATUS:BUSY
+CREATED:20221004T073016Z
+LAST-MODIFIED:20221011T063437Z
+DTSTAMP:20221011T063437Z
+DTSTART;TZID="(GMT +01:00)":20221004T140000
+DTEND;TZID="(GMT +01:00)":20221004T150000
+SUMMARY:Music School 
+CLASS:PUBLIC
+UID:0000021
+X-MOZ-SNOOZE-TIME:20221004T113000Z
+X-MICROSOFT-CDO-OWNER-CRITICAL-CHANGE:20221014T203413Z
+X-MICROSOFT-CDO-ATTENDEE-CRITICAL-CHANGE:20221014T203413Z
+X-MICROSOFT-CDO-APPT-SEQUENCE:0
+X-MICROSOFT-CDO-OWNERAPPTID:-1
+X-MICROSOFT-CDO-ALLDAYEVENT:FALSE
+RRULE:FREQ=WEEKLY;UNTIL=20221201T020000;BYDAY=TU
+END:VEVENT
+END:VCALENDAR

test/test22.ics

@@ -0,0 +1,26 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:Fictitious Recurrence Test Calendar
+BEGIN:VEVENT
+CREATED:20221018T221500Z
+DTSTAMP:20221019T171200Z
+UID:000021a
+SUMMARY:Party
+RRULE:FREQ=YEARLY
+DTSTART;TZID=Europe/Berlin:20220714T140000
+DTEND;TZID=Europe/Berlin:20220714T210000
+TRANSP:OPAQUE
+SEQUENCE:5
+END:VEVENT
+BEGIN:VEVENT
+CREATED:20221019T181700Z
+DTSTAMP:20221019T191200Z
+UID:000021b
+SUMMARY:Party next day
+RRULE:FREQ=YEARLY
+DTSTART;TZID=Etc/GMT-2:20220715T140000
+DTEND;TZID=Etc/GMT-2:20220715T210000
+TRANSP:OPAQUE
+SEQUENCE:5
+END:VEVENT
+END:VCALENDAR