> For the complete documentation index, see [llms.txt](https://docs.spike.sh/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.spike.sh/oncall-schedules/linked-calendars.md).

# Linked calendars

<figure><img src="/files/jRdG6VGete9iSim3cm31" alt="Linked calendars on Spike"><figcaption></figcaption></figure>

## Linked calendars

Linked calendars display external or holiday calendars as overlays on your on-call schedule. Use them to plan shifts around holidays, regional events, or company-wide leaves. They do not modify or affect any existing on-call shifts.

<figure><img src="/files/Yh2if7e2Z13pgP2r2WpJ" alt="Holiday calendar overlaid on an on-call schedule"><figcaption><p>A holiday calendar overlaid on the on-call schedule.</p></figcaption></figure>

### Adding a linked calendar

Visit the [Linked Calendars](https://app.spike.sh/oncalls/linked-calendars) section on your dashboard. You can upload an `.ics` file or link directly from Google Calendar or Outlook.

<figure><img src="/files/vEzopmvunAiRg4hPWGXT" alt="Link a calendar on Spike"><figcaption><p>Link a calendar from the Linked Calendars section.</p></figcaption></figure>

{% tabs %}
{% tab title="Upload ICS file" %}

1. Export your calendar as a `.ics` file from Google, Outlook, or another calendar app.
2. In the Linked Calendars section, click **+ Link a calendar** and choose **Upload file**.
3. Select your `.ics` file and click **Link**.

The imported calendar appears as an overlay. Toggle visibility anytime using the checkbox beside its name.
{% endtab %}

{% tab title="Link from Google Calendar" %}

1. In Google Calendar, go to **Settings → Integrate calendar**.
2. Copy the **Public address in iCal format**. The calendar must be set to public.
3. In the Linked Calendars section, click **Link calendar**, choose **From link**, and paste the link.
   {% endtab %}

{% tab title="Link from Outlook Calendar" %}

1. In Outlook Calendar, go to **Settings → View all Outlook settings → Calendar → Shared calendars**.
2. Under **Publish a calendar**, select the calendar and permissions, then copy the ICS link.
3. In the Linked Calendars section, click **Link calendar**, choose **From link**, and paste the link.
   {% endtab %}
   {% endtabs %}

{% hint style="info" %}
Spike only reads data from linked calendars. It cannot write, modify, or delete any events on external calendars.
{% endhint %}

### Managing linked calendars

All linked calendars appear in the [Linked Calendars list](https://app.spike.sh/oncalls/linked-calendars) below your on-call calendar.

* **Toggle on/off:** Use the checkbox beside a calendar name to show or hide it on the on-call view.
* **Refresh data:** Click **Refresh** beside a calendar to fetch the latest events. Spike refreshes all calendars automatically every 24 hours at midnight UTC.

Only users who can modify on-call schedules can add, delete, or manage linked calendars.

{% hint style="info" %}
Linked calendars are shared across the team. Toggling visibility, adding, and deleting linked calendars affects everyone's view.
{% endhint %}

### FAQs

#### Can I link multiple calendars?

Yes. All linked calendars appear as overlays on your on-call calendar.

#### Does linking a calendar change my on-call schedule?

No. Linked calendars are for reference only and do not modify or offset any on-call shifts.

#### How often do linked calendars refresh?

Calendars added via public links refresh automatically every 24 hours at midnight UTC. You can also refresh manually anytime by clicking **Refresh** beside the calendar name.

#### Who can add or manage linked calendars?

Anyone with permission to modify on-call schedules can add, delete, or manage linked calendars.

#### Can I hide a calendar without deleting it?

Yes. Toggle visibility on or off using the checkbox beside each calendar. The change applies to everyone in the workspace.