iCloud Calendar ICS Merger
Merge several .ics calendar files into one valid calendar, keeping one definition per time zone and optionally skipping events that repeat the same UID and changed-occurrence date.
- Keeps VTIMEZONE blocks
- Optional UID + RECURRENCE-ID de-duplication
- Conflict report
Your files are processed locally in your browser and are not uploaded to A2Z Tools.
ICS Merger workspace
Before you start
- Up to 50 files, 25 MB each and 50,000 events in total.
- When files use different calendar names or colours, the first file's are kept and the others are listed.
- Alarms, attendees and attachments are copied unchanged.
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Combine calendar exports into one file
People end up with several .ics files for many reasons: separate iCloud calendars for home and work, an old backup and a newer one, or a shared calendar received from someone else. Importing each file separately is slow and can create duplicates. The ICS Merger joins them into one valid iCalendar file that any calendar app can import in a single step.
How to get .ics files from iCloud Calendar
- On a Mac, open the Calendar app, select a calendar in the sidebar and choose File, then Export, then Export. Repeat for each calendar.
- For a calendar shared publicly from iCloud, open its public link in a desktop browser and save the .ics file it returns.
- Invitations and calendar attachments in email are .ics files too.
The merger works only with files you choose. It never connects to your Apple Account or to iCloud.
What happens during a merge
- Each file is summarised: calendar name, number of events, date range and the time zones it uses.
- Events, tasks and journal entries are copied as they were written, including alarms, attendees, attachments and custom properties.
- Time-zone definitions are kept once per name. If two files define the same zone differently, the first definition is used and the difference is reported.
- Calendar-level settings can only have one value, so the first file's name, colour, default time zone and method are kept and every other value is listed.
- With de-duplication switched on, an event whose UID and changed-occurrence date already appeared in an earlier file is skipped, and every skipped event is listed.
Time zones and repeating events
A merge does not convert times. An event written for Europe/Lisbon stays in Europe/Lisbon, and its definition travels with it. Repeating events keep their rule, excluded dates and changed occurrences, which stay linked to their series by UID. Changed occurrences are only skipped when the exact same occurrence is already present.
Checked before download
The merged calendar is written with standard line lengths and escaping, then read back by the same parser. The page shows the number of events and time zones it found, so you can compare it with the preview before importing. If the read-back does not match, the download is not offered at all, so a broken file never reaches your calendar app.
Limitations
- Up to 50 files, 25 MB each and 50,000 events in total.
- Look-alike events with different UIDs are not removed; the Calendar Duplicate Cleaner handles those.
- Importing the result adds events to your calendar app; the merger itself changes nothing in any account.
Privacy
All files are read and merged in your browser. They are not uploaded to A2Z Tools, and nothing remains after you leave the page.
A2Z Tools is an independent service and is not affiliated with or endorsed by Apple Inc. iCloud, iPhone and Apple are trademarks of Apple Inc.
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Key facts
- Merges up to 50 files, 25 MB each and 50,000 events in total.
- Keeps one VTIMEZONE definition per time-zone name and flags differing definitions.
- Optionally skips events with the same UID and changed-occurrence date.
- Lists conflicting calendar names, colours, time zones and methods; the first file wins.
- Reads the merged file back before offering it, to confirm the event count.
- Runs in the browser; the calendars are not uploaded.
How to use it
- Export each calendar from iCloud or your calendar app as an .ics file.
- Choose or drop the files, or try the two sample calendars.
- Put the files in order; the first file's calendar name and colour are kept.
- Review the preview, the conflict report and any skipped duplicates.
- Download the merged .ics file and import it into your calendar app.
Frequently asked questions
Will merging create duplicate events?
Only if you switch de-duplication off. With it on, an event whose UID and changed-occurrence date already appeared earlier is skipped and listed. Look-alike events with different UIDs are kept; the Calendar Duplicate Cleaner can find those.
Which calendar name and colour does the merged file use?
The first value found in file order. Move a file to the top to use its name, colour and default time zone. Every other value is listed in the conflict report.
Are time zones preserved?
Yes. Each time-zone definition is kept once per name and event times are not converted. If two files define the same zone differently, the first is kept and the difference is reported.
Are my calendars uploaded?
No. The files are read and merged in your browser on your own device and are not uploaded to A2Z Tools.
Does the merger add events to my iCloud account?
No. It creates a file. You import that file yourself in the Calendar app or another calendar service.
How many files can I merge?
Up to 50 files, each up to 25 MB, with no more than 50,000 events in total.
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