# Understanding calendar update intervals

## Overview: Reported synch issues[​](#overview-reported-synch-issues "Direct link to Overview: Reported synch issues")

Some users approach us regarding shared calendars not updating correctly or frequently enough.

In this article, we try to explain the background of these issues.

## Update mechanism[​](#update-mechanism "Direct link to Update mechanism")

Within freispace, you can export shared iCal links.

The links are then subscribed to by other services, meaning these *pull* the iCal link regularly to update the calendar entries. This means that Google and Microsoft retrieve the current calendar data themselves. freispace has no way of *pushing* changes to these services.

Within the iCal, we specify an update value of once per hours. This value was intentionally chosen to ensure that the load on our system remains within normal limits. However, most services disregard the set limit, including Google and Microsoft.

## Update frequencies for different services[​](#update-frequencies-for-different-services "Direct link to Update frequencies for different services")

### Google Calendar[​](#google-calendar "Direct link to Google Calendar")

* Typically updates iCal feeds **every 8 to 12 hours**.
* This update frequency is independent of settings such as `REFRESH-INTERVAL` or `X-PUBLISHED-TTL` that we use within our iCals.
* Currently, Google does not offer a way to accelerate this frequency.

### Outlook (Web Version)[​](#outlook-web-version "Direct link to Outlook (Web Version)")

* Updates iCal feeds approximately **every 3 hours**.
* Changes occasionally **can take longer than 24 hours** to become visible.
* For more information, refer to [Outlook Support](https://support.microsoft.com/en-us/office/import-or-subscribe-to-a-calendar-in-outlook-com-or-outlook-on-the-web-cff1429c-5af6-41ec-a5b4-74f2c278e98c).

### Outlook (Local/Desktop Versions)[​](#outlook-localdesktop-versions "Direct link to Outlook (Local/Desktop Versions)")

* There are no documented fixed intervals for updates.
* Based on our experience, the behavior is similar to that of the web version.

## Limitations[​](#limitations "Direct link to Limitations")

There are thousands of reports online from users expressing concerns regarding update intervals with Microsoft and Google.

We understand that the update intervals can be frustrating, however **freispace does not have direct control over these retrieval intervals**.