How do I highlight an entry in the calendar on my iPad?

Just to Clarify, the tiny dot will appear beside your appointment if you are specific with the appointment times. The highlighted bar will appear if all day event is checked off. hope this clears things up.

A pinhole sized colored dot... total fn joke.. (thats on an ipad).. whos in charge of this dog

You can't with the built-in calendar app. You might be able to do this with an app like Week Calendar: https://itunes.apple.com/us/app/week-calendar/id381059732?mt=8. (It's the "Swiss Army knife" of calendar apps.)

Perhaps I misunderstood you. Are you talking about using different colors for your different calendars?

This article explains how to assign colors to calendars: http://help.apple.com/icloud/#mmfbbb3c60. An event on your iPad iCloud calendar will have colored dot in the month view if it is a timed event. It will have a colored dot and bar ("highlight") if it is an all-day event.

Sums it up in a nutshell. Mother's Day in a blazing pink highlight and an important meeting with a poxy little dot.