Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Whitehorse to Washington, D.C. as you normally would.
Whitehorse (YXY) is the airport you will fly out of if you book a flight from Whitehorse to Washington, D.C.. You should not have trouble finding flights to Washington, D.C. from Whitehorse; the airport handles an average of 0 outbound flights to Washington, D.C. per day. You should also have plenty of airline options to choose from since 0 airlines have flights from the Whitehorse airport to Washington, D.C.. It is only a 1.0 km journey to Whitehorse (YXY) from Whitehorse’s city centre.
These are just IATA (International Air Transport Association) codes. They are used in aviation to identify and differentiate airports. That’s why a Whitehorse Airport to Washington, D.C. Dulles Intl Airport flight would often be abbreviated as a YXY to IAD flight. While you’re still figuring out your travel plans, it’s not a bad idea to learn the names and codes of other airports around these areas: Baltimore/Washington Airport (BWI), Washington, D.C. Reagan-National Airport (DCA).