If you set up the calendar connection according to our basic instructions, the update interval will remain entirely under the control of Google, which usually means a range of 2-24 hours - and we understand that this does not meet the demands of professional practice.
We have therefore found and tested a solution for you, or rather for your IT department, in the form of a 3rd party script (credit goes to Mr. Derek Artican and his contributors) - see his website:
Note: We present this option "as is"; without follow-up tech. support from our side and at the user's own risk.
And here is the procedure to ensure an update in an interval of 15 minutes:
1. Create a new calendar in Google Calendar using the "+" icon.
and the Create New Calendar command. The name is up to you.
2. Open this link:
3. From the menu, select File => Make a copy. If you are logged in to your Google account, a copy will open in the Script Editor, which you can now edit.
On line 23, insert the link to the calendar between the first quotes (in SingleCase it can be found in Menu (=your name in the top right) => Mail and Calendar Settings => Calendar Synchronization) and between the second quotes the exact name of the calendar created in step 1.
Delete lines 21 and 22.
4. Then, command Run => Run function => install and then Check permissions.
Select the account whose calendar you want to transfer data to and then click Advanced options, then Go to website...
5. Click the Enable button. That's it.