[ Back to all articles ](https://addcal.co/blog.md) outlook subscription calendars ics troubleshooting Outlook Internet Calendar Not Updating? Why, and the Fix ======================================================== By Tom •November 13, 2026 An Outlook internet calendar subscription is not updating because Outlook only re-reads the feed on its own schedule, and that schedule is slower than most people expect. For Outlook.com, Outlook on the web, the new Outlook for Windows and the mobile apps, Microsoft's own number is about every three hours, with a note that it can take more than 24 hours. Classic Outlook for Windows is different: it follows the interval the calendar's publisher recommends, and you can override that. Nothing in either Outlook refreshes a subscription the moment the owner changes an event. This guide tells the two Outlooks apart, gives the fix for each, and covers the three cases where the problem is not the schedule at all: you imported the file instead of subscribing, the source feed has not changed, or the subscription has gone stale and needs re-adding. UI labels checked in November 2026. First, which Outlook are you in ------------------------------- The fix depends on this, so settle it before anything else. - **Outlook.com, Outlook on the web, the new Outlook for Windows, Outlook for Mac on a Microsoft account, and the iPhone and Android apps.** The subscription lives on Microsoft's servers. Every one of these apps shows the server's copy, and the server decides when to fetch the feed again. There is no refresh button because the apps do not do the fetching. - **Classic Outlook for Windows** (the desktop program with the File menu and the ribbon). The subscription lives on your PC. Outlook itself fetches the feed as part of Send/Receive, and there are settings for how often. If you are not sure which you have on Windows, look at the top right. The new Outlook has a toggle labelled **New Outlook**. Classic Outlook has a **File** tab at the far left of the ribbon. Outlook.com, the web and the new Outlook: the schedule and the only fix ----------------------------------------------------------------------- Microsoft's help page for subscribing to a calendar in Outlook.com says updates "should happen approximately every 3 hours" and, in the same breath, that "this update can take more than 24 hours". Both are true. The server polls each subscribed feed on a rolling schedule, and a feed that was polled a minute before you changed the event will not be polled again for hours. There is no setting that shortens it and no manual refresh. Clicking the calendar, reloading the page, signing out, or opening the mobile app makes no difference, because all of them show the same server copy. What you can do: 1. **Wait a day before treating it as broken.** If the change appears within 24 hours, the subscription is working as designed. 2. **Remove the calendar and subscribe again.** This is the only way to force a fresh fetch. In the calendar's left pane, hover the subscribed calendar, open its menu, choose **Remove**. Then **Add calendar**, **Subscribe from web**, paste the feed address, **Import**. The re-added calendar is fetched immediately and then goes back onto the schedule. Any colour, name or notification settings you had on it are lost, and so is anything connected to the old copy, like a Power Automate flow. 3. **If updates never arrive, even after a day, go to the stale-subscription section below.** One thing that is not a fix: subscribing a second time without removing the first. Outlook.com will tell you the calendar already exists, or create a duplicate that is on the same schedule. Classic Outlook for Windows: the Update Limit setting ----------------------------------------------------- Classic Outlook fetches internet calendars itself, during Send/Receive, and it respects a recommended refresh interval that the calendar's publisher puts inside the feed (the `X-PUBLISHED-TTL` property, if you ever open the file). That recommendation is enforced by a checkbox called **Update Limit**, and that checkbox is why a classic Outlook subscription can sit unchanged for hours while the publisher's site shows the new event. 1. **File**, **Account Settings**, **Account Settings** again in the dropdown. 2. Open the **Internet Calendars** tab. Every subscribed feed is listed with its address. 3. Select the calendar and click **Change**. 4. Under **Update Limit**, untick **Update this subscription with the publisher's recommendation**, then **OK**. With the limit off, Outlook refreshes that feed on every Send/Receive, which runs every 30 minutes by default and whenever you press **F9** (Send/Receive All Folders). So the practical fix in classic Outlook is: untick the limit, press F9, and the change is there. Two cautions. A publisher sets that interval for a reason, usually load, so leave the limit on for feeds you only need daily, like a holiday calendar. And a feed whose publisher recommends a short interval already refreshes often; AddCal feeds, for instance, declare 15 minutes, so with the limit on a classic Outlook subscription to an AddCal calendar updates within about half an hour of a change without you touching anything. You imported the file, you did not subscribe -------------------------------------------- This is the most common reason a calendar never updates, and it is not a bug. Outlook offers two different things for an .ics address: **Subscribe from web**, which keeps a link to the feed and re-reads it, and **Upload from file** (or double-clicking a downloaded .ics, or **Open Calendar**, **From Internet** in classic Outlook with the wrong choice at the prompt), which copies the events once and never looks at the source again. Microsoft's page puts it plainly: when you import an .ics file, your calendar does not refresh the imported events, even if the owner updates them. How to tell which you have: an imported calendar is just events in your own calendar, or in a plain calendar you own. A subscription is a separate calendar in your list with its own name, and in classic Outlook it appears on the Internet Calendars tab. If it is an import, delete those events and subscribe to the feed address instead. The address usually starts with `https://` or `webcal://` and ends in `.ics`; Outlook.com accepts either. The source has not changed -------------------------- Before blaming Outlook, confirm the feed itself carries the change. Paste the feed address into a browser or into an [ICS viewer](https://addcal.co/tools/ics-viewer.md) and look for the event. If the new time is not in the feed, the problem is upstream: the owner edited a different calendar, the change has not been published, or the service that generates the feed has its own delay. If the new time is in the feed, Outlook has simply not fetched it yet, and the sections above apply. This also catches the case where you subscribed to an old address. Calendar services sometimes rotate feed URLs when a calendar is re-shared or its privacy setting changes, and the old URL keeps serving a frozen copy or an empty one. The subscription has gone stale ------------------------------- Occasionally an Outlook.com subscription stops updating permanently: the feed is fine, 24 hours pass, nothing changes. Microsoft's forums are full of these, and the consistent answer is the one above, remove and re-add. Three things make it more likely, and are worth fixing on the publisher's side if you own the feed: - **The feed address redirects or needs a login.** Microsoft's fetcher wants a plain, public, HTTPS address that returns the file directly. A URL that bounces through a login page, or whose certificate has expired, fails silently and the subscription keeps the last good copy. - **The feed is very large.** Thousands of events, or years of a recurring series expanded into individual entries, slow the fetch down and get it deprioritised. Keep a published feed to the events people need. - **The feed's events keep changing identity.** Each event in an .ics file has a `UID`. If the publisher regenerates UIDs on every edit, Outlook sees a delete and a create, not an update, and some clients handle that badly. A well-behaved feed keeps the UID and bumps the `SEQUENCE` or `LAST-MODIFIED` value. How Outlook compares with Google and Apple ------------------------------------------ The three-hour figure sounds slow until you compare it. Google Calendar re-reads a subscribed URL every few hours, sometimes not for 24, and has no manual refresh at all. Apple Calendar on a Mac or iPhone lets the subscriber choose the interval, down to every 5 minutes, and refreshes on demand. Outlook.com sits between them. If you publish a calendar and your audience is mixed, write "changes can take up to a day to reach your calendar app" next to the subscribe link and you will have covered all three. If you are the one publishing the calendar, the single most useful thing you can do is make urgent changes somewhere other than the feed. AddCal, which we make, handles the urgent case with emailed invites: when an invited event changes, the invitee gets an update straight away, because the feed cannot be relied on to carry a same-day change. The [subscription calendars](https://addcal.co/solutions/subscription-calendars.md) page covers how that works, and our help centre has the [refresh times for every major app](https://help.addcal.co/en/articles/11933752-calendar-subscriber-update-delay) in one table. Frequently asked questions -------------------------- ### How often does Outlook update an internet calendar subscription? For Outlook.com, Outlook on the web, the new Outlook and the mobile apps, Microsoft says approximately every 3 hours, and that it can take more than 24 hours. Classic Outlook for Windows updates on each Send/Receive, every 30 minutes by default, unless the Update Limit setting holds it to the publisher's recommended interval. ### Can I force Outlook to refresh a subscribed calendar? In classic Outlook for Windows, yes: untick Update Limit for that calendar under File, Account Settings, Internet Calendars, then press F9. In Outlook.com, the web, the new Outlook and the mobile apps there is no refresh control. Removing the calendar and subscribing again is the only way to force a fetch. ### Why does my subscribed calendar show old events after the owner changed them? Either Outlook has not reached the feed on its schedule yet, which resolves within 24 hours, or you imported the .ics file instead of subscribing, which never updates. Check your calendar list: a subscription appears as its own named calendar. If the events are in your own calendar, it was an import. ### Why is my Outlook internet calendar subscription not updating at all? First confirm the feed itself has the change by opening its address in a browser. If it does, remove the calendar from Outlook and subscribe to the address again. If it still never updates, the feed address is probably redirecting, requiring a login, or serving an expired certificate, all of which make Microsoft's fetcher give up silently. ### Does the new Outlook for Windows refresh internet calendars differently from classic Outlook? Yes. The new Outlook stores subscriptions on Microsoft's servers, like Outlook.com, so it refreshes on the server's roughly three-hour schedule and has no Update Limit setting and no manual refresh. Classic Outlook fetches feeds itself during Send/Receive and lets you change the interval. ### Is a subscribed internet calendar in Outlook read-only? Yes. You can view the events and copy one to your own calendar, but edits have to be made by the calendar's owner at the source, and they reach you on the next refresh. Outlook is a trademark of the Microsoft group of companies. Steps and quotes checked against Microsoft's Outlook.com subscription help page in November 2026. Last updated on November 13, 2026 ![Tom](https://cdn.addcal.co/static/authors/atymic.jpg)### Tom Founder Built Calndr.link in 2020 because an event link broke in Outlook and it annoyed him enough to fix it properly. Six years later he can tell you exactly how each calendar app mangles a timezone, which is a worse party trick than it sounds. Otherwise found hanging off a rock somewhere in Australia. [GitHub](https://github.com/atymic)[X](https://x.com/atymic) ### Related articles [ICS Not Working in New Outlook? Why, and the Fix Double-click an .ics and new Outlook does nothing, or says it imported and shows no event. Half the time the import dialog is open on a tab you cannot see. The rest of the time the file has one of four faults classic Outlook forgave. How to tell which, and the fix for each.](https://addcal.co/blog/ics-not-working-in-new-outlook.md)[Webcal Link Not Working on iPhone? How to Subscribe, and the Fix A webcal link that does nothing on an iPhone was tapped inside an app's browser. How to subscribe by hand from the Calendar app, what to do when Find fails or no events show, how to refresh faster, and how to remove a junk calendar.](https://addcal.co/blog/webcal-link-not-working-on-iphone.md)[ICS Timezone Wrong in Google Calendar: Why Events Shift, and the Fix An imported .ics lands at the wrong time in Google Calendar for one of three reasons: a zone name Google does not know, a floating time read in your zone, or a bad daylight-saving rule. How to tell which, and the fix for each.](https://addcal.co/blog/ics-timezone-wrong-in-google-calendar.md) [ Browse all articles ](https://addcal.co/blog.md)