Hi stephanie119,
Thanks for reaching out to us here. Welcome! I can understand the benefit of having a calendar feature in QuickBooks Online. Although this currently isn't available, you can use a third-party app that can integrate with our program. If you would like to see this feature available in future updates, please don't hesitate to submit a suggestion to our Development Team. You can do this by clicking on the Help menu and select Feedback.
I'll keep this thread open, so other Community members can provide their advice and suggestions as well.
If you have any other questions, feel free to reach out again. We would be glad to help!