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.
Tango paid seat selection is only available when booking directly at aircanada.com/agents. All passengers including those booked on Tango fares can use web check-in and select their seat up to 12 hours before departure. Click here for more information on Air Canada s web check-in.ango paid seat selection is only available when booking directly at aircanada.com/agents. All passengers including those booked on Tango fares can use web check-in and select their seat up to 12 hours before departure. Click here for more information on Air Canada s web check-in.
1 You may stand by if seats are not available in the purchased fare class. 2  In these cases, the same-day change fee will apply, but will not be charged unless you are assigned a seat on your alternate flight.