Manual Calendar Update
Desktop calendars will update if you
quit and restart the application. Other
options vary by operating system and calendar
program.
Manual Refresh Settings
Apple Calendar on Mac
Go to Apple Calendar >
click View > click Refresh
Calendars.

Apple Calendar on iPhone
Open
the Calendar app on your iOS
device > touch the "Calendars"
button at the bottom > swipe down on the
screen and release. The refresh icon swirls at
the top of the screen while updating.

Outlook Calendar on Desktop
Go to Calendar > go to Send/Receive > click Send/Receive All Folders.

You will know when the refresh occurs by
a pop up:

Outlook.com Calendar on Desktop
Go to Outlook.com Calendar > click settings dial > click Refresh.

If doesn't refresh try this link for more
help, click
here.
Google Calendar on Desktop
You cannot do a manual calendar
refresh. For
sync issues, click
here.
Google Calendar on Mobile
You cannot do a manual calendar
refresh. For sync issues, click
here.
Outlook on Mobile
You cannot do a manual calendar refresh.
For sync issues, click
here.
Outlook.com on Mobile
You cannot do a manual calendar
refresh. For sync issues, click
here.
Yahoo Calendar on Mobile and Desktop
To manually refresh click on arrow next to 'Other Calendars' > click/tap Refresh.

For sync issues, click
here.