You tagged your question as "New Outlook for Windows". If this is correct, then the Q&A Assist answer is incorrect, as it is for Classic Outlook.
Click the [No] button on the "Was this answer helpful?" bar under the Q&A answer. If there is a [Reject] button visible, click that too. This should signal the forum moderators that you want a human to pick up this question.
But I don't think that will do you any good. You can't change the Calendar Font in New Outlook for Windows. Best you can do is Vote for and Comment on this Feature Request
Calendar Font Size
https://feedbackportal.microsoft.com/feedback/idea/cbf7b559-6706-f011-a4de-6045bdb3947a
(You must "Sign In" at the top right of the Feedback page before you can vote).