Calendar events appear stacked and overtyped on my iMac

Hi, and welcome to this Apple (user-to-user) Community!

Re: "Calendar events appear stacked and overtyped on my iMac"

Seems your calendar is displayed in "Month" view, which just gives us a good overview of events

I see some days on your calendar have two or three separate events, and some seem to be repeats of others

If you want to see a whole day's events more clearly, you can use "week" view or "day" view, making it easier to plan the day, and add to, edit, or delete etc, all of the listed events

As Apple users, like yourself, in the community, we do not know which MacOS version is installed on your iMac:

eg: For the latest MacOS Sequoia:

You can: Go to specific dates or change views in Calendar on Mac - Apple Support

Eg: says:

"In Day or Week view,

you can also swipe left or right on a trackpad or Magic Mouse. In Month view, you can swipe up or down. (Swipe slowly to stop between weeks, months or years.)

Switch from Week view to a day in Day view: Double-click the day’s date.

Switch from Month view to a day in Day view: Double-click the day’s date."

You can take control of the settings you have in place for the calendar, by clicking "Calendar" (on the left in the top menu bar), and choosing "Settings" from the drop-down window

If you want to become more familiar with using the calendar app's features:

There's a useful: Calendar User Guide for Mac - Apple Support online

You can click "Table of Contents" at the top of the welcome page thhat opens from the abov link

For accurate info: You can choose your correct MacOS version at the top of articles

Hope this helps :-)