I was also wondering the same thing. Not sure if what I'm about to write is correct, so please take it with a word of caution. There are two graphs under the view, Trip Dates and Search Dates.
Let's start with the Search Dates. This historical graph has time (in days) on the x-axis and 3 variables on the y-axis. The three variables are number of views, number of requests and number of bookings. When a potential guest searches for a place to stay, if your listing pops up and they click on it, this graph will increment the views variable. If the guest goes on to request your listing, the graph will increment the request variable. Lastly, if you get a booking the graph will increment the booking variable. Everyday, the graph will show you the total values of each variable. This graph is historical, meaning it only has data from when you started the listing until the present moment in time. Its called Search, because its based on your listing being a result of searches of potential guests.
The other graph is the Trip Dates graph. This one might be easier to understand by viewing it as you read this. Back up this graph before you made your listing. The graph should only have a redline. This redline is the average number of views in your area - we'll call this average views. Now, move the graph to the point where you added your listing. Your graph should (hopefully) have some views of your listing - we'll call this 'your views' - shown with bars. You'll notice that there may be some difference in the number of your views and the average views. This is expected because it's a new listing. Over time, your views and the average views might start to come closer together. If you happen to be the first person to AirBnb in your area, then there might not be a difference. I believe, there are at least 3 possibilities for this graph:
1. Average views are much higher than your views = This might be totally normal in the beginning, but if it's still happening after your listing has been up for some time, then I would investigate this further. Check your price and pictures. I would imagine they are the top things guests look at.
2. Average view the same as your views = This means that your listing is right there with everyone else. I believe this is where things should be. I'm not an economist, so there might be some pricing theory or supply/demand curve out there that says otherwise.
3. Average views are way lower than your views = This means that your listing is hot! Something is making people look at your listing. Keep up the good work!
Another intersting thing about the Trip Dates graph is that is seems to forecast the future. AirBnb has tremendous data to work with and must be able to forecast the views your listing will get in the future based on a myriad of variables. Lastly, I believe it's called Trip Dates, because it based on what actual dates potential guests are using when looking for a place to stay.
If anyone has felt something is in error, I would appreciate a note for correction. Thank you and happy travels! 🙂