Once you select your itinerary, dates, cabin class and passengers, the search results page will show at the top the lowest price for all passengers for this particular search. On that page, you can also opt to see prices for the “Previous day” and “Next day” for each flight.
You can also try the “My dates are flexible” option on the Book a flight(opens in the same window) page, which will show results for +/- 3 days of the initial search.