While I'm thinking about it... on the month view, what do the bars on each day show?

I'd think it'd show if I have AM (left side shared), PM (right side shared), or all day (both sides shared) events. Except this is not the case.

Example: On June 11, I have a 9:30am, 10L30am, 11:30am, 12:00p, 4:00pm, and 4:30pm sent of events. The month calendar for this date shows a rectangle with the left side as white and the right side as browish-yellow.

On June 27, the rectangle is fully browish-yellow, yet I have only a 10:00am and an 11:00am meeting (plus an all day event that's marked as "free").

On June 13, I have that same all day event, plus other meetings throughout the morning. I get LEFT side as brown-yellow and right side as white.

Can this be explained? Is this showing me something i haven't figure out?