The light-year is a unit of length used to express astronomical distances. It is about 9.5 trillion kilometres or 5.9 trillion miles. As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (365.25 days). Because it includes the word year, the term light-year is sometimes misinterpreted as a unit of time.
You can select your seat online if: 1  You book your flight on aircanada.com., and. 2  You re travelling on: 3  Seat selection is not available on codeshare flights.4  an Air Canada or Air Canada rouge flight, or. 5  an Air Canada Express flight operated by Jazz, Sky Regional, Air Georgian Ltd. or Exploits Valley Air Services Ltd.ou can select your seat online if: 1  You book your flight on aircanada.com., and. 2  You re travelling on: 3  Seat selection is not available on codeshare flights.
Book early for the best selection of seats. If you want to change your seat assignment after you've booked your flights, go to United Airlines' website and enter your reservation number. You can then go to your seat reservations and make new selections. In some cases, all the free seating (the white boxes) will be taken for a flight.