Setting the event end time to 00.00 is known as swith day event in WebScheduler and it will be rendered in all day event section.

Regarding your scenario, you will need to modify the shipped editing form to accept HH:mm:ss format instead of the HH:mm format or you will need to create a custom editing form that will allow you to set the end time to 23:59:59.

We have provided some article regarding custom editing form in article "EditingForm" in WebScheduler documentation or in the blog.

I am shocked...a professional, time tested web scheduler handles 12 AM this way? Setting the time to 23:59:59 will make my calculations ugly, then I have to start rounding and dropping decimals and such. Very disappointing.

I have forwarded your comment to the developer. Such behavior will be discussed for implementation in the future revision of WebScheduler.

The current behavior is done because 12AM is already considered as the next calendar day. Such event will be considered as a switch day event and will be rendered in the all day event area section.