Google offers the specific examples of taking note of the time of day so to not provide you info for breakfast spots at dinner time. They also explain that they will not promote a day in the park if there is bad weather rolling in.
Check out my Android Authority post on this for more details.
Other than the contextual aspect to this new feature, I am unsure how it differs from the existing Nearby features of the Maps search functionality. Also, I was out and about all day yesterday, still haven't seen this new button. Perhaps I did not enter a relevant zone at the right time, or maybe the roll out is taking a little longer than expected.
We are still unsure if the new features will be a part of an upcoming Maps app update, or if Google has it all under control on their end. Either way, we're truly looking forward to seeing it in action. This is particularly handy when you are getting to know a new area or are just on vacation and looking for the best things to do in the area.
Do you believe that features like this are worth turning on your Location and History settings, allowing Google to track your every move? (I do!)