If a passenger does not know the exact date of his return, you can purchase a ticket with open date. Flights with an open date, in most cases, are made by 3 months, 6 months and 1 year. During the selected period, the passenger may be in the airline or agency that sells tickets to book a place on the number of interested and suitable flight. Using this ticket you will not have to take an additional charge, except when the chosen flight no place in the class. In this case, you pay the difference in ticket price.
The cost of tickets with open date is more expensive than flights with a fixed date. As practice shows, buying a ticket with an open date on both sides often cheaper than a ticket to purchase a separate "place" and a separate ticket "back."
Your ticket with an open date of departure, booking of seats on the flight in accordance with the availability of marked on the ticket booking class. Use open ticket only after it will make the flight number and date of departure.
"Miy Kvytok on a plane" offer you, provided you do not know the exact dates of departure back to buy airline tickets with open date of return flight.