Why your Outlook calendar is hours out of date in Google Calendar

You added your Outlook calendar to Google with its ICS link. It showed up, and then it stopped keeping up. Nothing is broken: this is how calendar subscriptions work.

What is actually happening

A calendar added with From URL is a subscription. Google stores the link and fetches it again on its own schedule, which in practice is somewhere between every 8 and 24 hours, and can be longer. Between fetches Google shows whatever it got last time. So a meeting that moved at 9 this morning stays put in Google until Google's next visit, which might be tomorrow.

Google does not publish the interval and offers no way to shorten it. There is no refresh button for subscribed calendars, in the web app or on mobile.

Things that do not help

• Removing and re-adding the calendar. You get one fresh fetch, then the same schedule again.
• Re-publishing from Outlook. Outlook's side is usually up to date within minutes; the wait is on Google's side.
• Changing the link (for example to the HTML version). Same mechanism, same delay.
• Waiting for a fix. This has behaved the same way for well over a decade.

The fix

Stop asking Google to fetch and start writing the events in. A sync service signs in to both calendars with your permission and uses the calendar APIs to copy every change across as it happens, so Google is updated in real time instead of within a day.

calendarnexus does exactly that, Outlook into Google (and Google into Outlook too, if you want), with no account to create. Connect Microsoft, connect Google, and a calendar named Outlook appears in Google and stays current. Once it has done its first run, remove the old subscription. The first 30 days are free, then it is from 70p a month.

Want the whole picture? See the four ways to sync Outlook to Google.