iCal Merger

THE PRACTICAL GUIDE · NORMANDIN SYSTEMS

Get more from iCal Merger

iCal Merger combines supplied ICS files into one calendar file while allowing a calendar name, description, and a choice about regenerating event UIDs. It is useful when you need one importable container for events that currently live in several exports. Keep the original files and begin with a small sample containing clearly different event titles. Combining components is not the same as deciding which duplicate or conflicting event is authoritative. Matching identifiers, recurring series, exceptions, and timezone definitions can affect how the receiving calendar interprets the merged file. Review the output in a separate test calendar before adding it to a schedule that already contains related events.

Guide updated October 13, 2026

How to use this tool

1. Add the ICS files to the file list and retain the originals. Remove any file that should not be included.
2. Set the optional calendar name and description, and review whether Regenerate UIDs is appropriate for the intended import.
3. Run the merge and inspect any reported errors. Review the merged content before copying or downloading it.
4. Import into a separate test calendar and check duplicates, event times, recurring series, and modified instances before using the result in a working calendar.

SEE IT IN PRACTICE

A worked example

One ICS file with Event A and another with Event B

A combined calendar containing the two event components

The combined file should retain both events. Matching identifiers and recurrence components require closer review.

Merge containers without assuming conflict resolution

Two files can contain unrelated events, duplicate events, recurring series, or exceptions to the same series. Combining them into one calendar does not automatically decide which version is authoritative. Review event identities and date ranges before merging. Keep source files so an unexpected import can be traced back to the calendar that supplied the component.

Inspect identity and recurrence after import

The interface offers calendar naming information and a regenerate-UIDs choice. That choice can affect how a receiving client matches items already present in a calendar. Test the merged file in a separate calendar before adding it to a working schedule. Compare event counts, duplicate titles, recurring instances, and timezones rather than judging only whether the download succeeded.

Event identity and duplicates

Calendar clients use identifiers such as UID to decide whether components describe the same event or separate events. Combining files with matching UIDs can therefore behave differently from combining two unrelated events. Keep source files until an import has been reviewed, and test both recurring and nonrecurring components. A merged file is a container, not a guarantee of conflict resolution.

When this tool is useful

• Prepare a combined import file while retaining a separate copy of the source.
• Use a small example to troubleshoot duplicate calendar-component issues and identify a representation mismatch.
• Create consolidated event collections without manually rewriting every field or symbol.

Tips for a better result

• Merging does not necessarily deduplicate identical events or reconcile competing updates. Event UIDs and time-zone definitions can affect how an importer handles the result.
• Keep original files and test the merged file in a separate calendar before adding it to an important calendar.
• Regenerating UIDs can create new identities for imported events. Keep that choice consistent with whether you intend to update existing items or add separate ones.

Frequently asked questions