Hi @sarah ,
This is a good question and one that we debated a bit when we first put together Ladybug. The short answer is that analysis period from 9AM to 3PM includes both 9AM and 3PM. So, if you don’t want the sun position from 3PM to be included, you should use an analysis period going to 2 PM.
The longer answer is that we’ve used a convention throughout Ladybug where any hour that you input represents an exact time that you want to be included in your study. So an Analysis Period from 0:00 to 23:00 actually includes the whole day without the need to make up a time at 24:00, which doesn’t really exist. The other benefit is that an Analysis Period from 9:00 to 9:00 is still valid. It just includes the data for the time at 9:00.