How to visualise this data on a single stacked histogram?

Hi Peter,

That's correct. Basically I've got a number of applications in production which could be stopped/started at any time of day, and I want to be able to report on/visualise when this has happened.
Stacking the stop/start events for an individual application was an idea I had in an attempt to 'declutter' the chart, as when I have lots of applications the chart gets a bit busy otherwise.

Stacey - thanks for your input too.

Best regards,
Steve