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.ics

Calendar Event

Email & Calendar

ICS is iCalendar data containing one or more events. One-time import differs from subscribing to a calendar URL; decide whether ongoing updates are required.

What it is used for
Exchange of events, recurrence and timezone information
What the file contains
Text
All sections, questions and sources

Content reviewed： · Editor：Kai

First: choose for your purpose

ICS exchanges calendar events. A one-time file import differs from subscribing to an updating calendar URL. Test in a separate calendar before adding events to your main schedule.

Opening steps

Choose your environment or purpose to see its steps.

Google Calendar: import on a computer

Choose the destination calendar first.

  1. Open Google Calendar settings on a computer and choose Import & export. Create a test calendar if needed.
  2. Choose the ICS, confirm the destination and import once; avoid repeated imports of the same file.
  3. Check event counts, start/end times, all-day events and recurrence. Later file changes are not automatically synchronized.
Mac: import into Calendar

Check which calendar receives the events.

  1. Save an ICS copy and use File > Import in Calendar.
  2. Select the file and destination calendar.
  3. Inspect alerts, time zones and recurrence end dates before relying on the imported schedule.
Mobile: distinguish invitations, subscriptions and files

An Add action is not necessarily synchronization.

  1. Identify whether you received an ICS attachment, an event invitation or a subscription URL.
  2. Preview in a compatible calendar and check title, time and destination. Use a computer if file import is unsupported.
  3. For changing schedules, use the provider’s supported subscription method. Keep imported events separate when resolving duplicates.

Menu labels and support vary by app, OS and version. Preserve the original before making changes.

Troubleshooting by symptom

  • Shifted times: compare event timezone/UTC values with device timezone settings.
  • Duplicates: check whether the same file was repeatedly imported.
  • No updates: importing a file is not automatic synchronization.
  • Duplicate events appear: the ICS may have been imported repeatedly. Back up and identify the affected calendar and scope before cleanup.
  • Times shift by hours: inspect source/destination time zones, UTC, daylight saving and all-day status before editing numbers.
  • Organizer changes do not arrive: importing a file is not ongoing synchronization. Check whether updates use invitations or a subscription URL.

Import or export ICS

  1. Import into the intended calendar and check dates, recurrence and reminders.
  2. Export the intended calendar and inspect which events are included.
  3. Verify time zones and all-day dates, and check whether changing schedules require subscription rather than a snapshot.

Reminder/recurrence support can differ; inspect exports for private events.

Import, subscription and invitation

Import copies a snapshot of events. Subscription retrieves updates from a provided URL, with service-specific refresh and editing behavior. Invitations may support attendance responses and organizer notifications. Choose according to your purpose.

Source for these steps：Google · Import events into Google Calendar / IETF / RFC Editor · RFC 5545 — iCalendar

Test without disrupting your schedule

For large imports, use a dedicated calendar and check the first/last event, recurring series and all-day dates. Keeping them separate makes visual comparison easier.

ICS can include meeting links, attendees, locations and notes. Export only events and fields intended for sharing, and avoid disclosing private subscription URLs.

Source for these steps：IETF / RFC Editor · RFC 5545 — iCalendar

Related-format differences

Related-format differences
Format / choicePurpose and preserved information
ICSEvent interchange; file import generally copies a snapshot.
Subscription URLRetrieves provider updates; frequency and editing restrictions vary.
CSVColumn-based migration; verify recurrence and field support.

Handling and security

Review invitation URLs and reminders; check public exports for meeting links, locations, attendees or private events.

Questions and answers

Does importing ICS enable synchronization?

No; one-time import differs from subscription.

Why are event times shifted?

Inspect event and device timezone settings.

Is ICS a contact card?

No; VCF is the contact format.

Does importing ICS automatically update events?

A one-time import does not establish automatic updates. Check the provider’s subscription URL or invitation workflow.

How can I test an import safely?

Import into a new dedicated calendar and inspect times, counts and alerts. This keeps the imported scope easier to identify.

Format facts: name, steward and MIME type
Formal name
iCalendar
Steward / specification
IETF (RFC 5545)
MIME type
text/calendar

Primary and official sources