You subscribed to your Canvas calendar in Google Calendar, and now a new assignment is missing, a due date is wrong, or nothing shows up at all. This is one of the most common Canvas questions, and it almost always comes down to one of the problems below.
First: how the sync actually works
Canvas gives you a private Calendar Feed link. When you add it to Google Calendar with From URL, Google doesn't connect to Canvas live. It downloads a copy of the feed every so often and shows that copy. So there is always some delay, and Google decides how often it checks, not you and not Canvas.
1. Google hasn't refreshed yet
This is the number one cause. Google refreshes subscribed calendars on its own schedule, and new or changed assignments can take several hours, sometimes close to a day, to appear. There is no refresh button for URL calendars.
Fix: wait a few hours before assuming it's broken. If you need something up to the minute, check Canvas directly or use an app that reads your feed more often.
2. You added it in the Google Calendar phone app
The Google Calendar app on iPhone and Android can't add a calendar from a link. If you pasted it somewhere in the app, it didn't subscribe.
Fix: on a computer, open Google Calendar, click the + next to "Other calendars", choose From URL, paste the Canvas link and click Add calendar. It then shows up on your phone too.
3. The calendar is hidden on your phone
Subscribed calendars sometimes start switched off in the mobile app.
Fix: open the Google Calendar app, tap the menu, scroll to your Canvas calendar and make sure it's checked. On iPhone, also check that the account is set to sync.
4. You copied the wrong link
The link must be the Calendar Feed link. It looks like https://yourschool.instructure.com/feeds/calendars/user_...ics. A link to the Canvas calendar page itself won't work.
Fix: in Canvas on a computer, open Calendar and click Calendar Feed at the bottom right. Copy that link. See how to find your Canvas Calendar Feed link for screenshots in words.
5. The assignment has no due date
The feed only includes things with a date. Readings, worksheets or tasks a teacher posted without a due date never reach any calendar.
Fix: skim each course's Modules once a week and add undated work to your own list.
6. The course isn't published or you joined late
Assignments from unpublished courses, or courses you were added to after subscribing, can take a while to appear in the feed.
Fix: confirm the course shows on your Canvas Dashboard. If it does and it's been more than a day, remove the calendar in Google and add the same link again.
7. Times look off by a few hours
If due times are shifted, your Canvas time zone and Google time zone don't match.
Fix: in Canvas, go to Account > Settings and set your time zone. In Google Calendar, check Settings > General > Time zone.
8. You reset your feed link
If you or your school reset the feed, the old link stops updating but stays in Google with old data.
Fix: delete the old Canvas calendar in Google and subscribe again with the new link.
A faster option
Google Calendar is good for seeing your week, but it was never built for homework: you can't check things off, and updates lag. lum9a reads the same Canvas link and turns every assignment into a checklist that updates often, with reminders before things are due. You can keep Google Calendar too.