On the airline ticket where it says "Date of Issue", the "Year" is also printed.

For example, if your ticket is issued 14NOV01, and your flight segments are say 01APR and 15APR, it would be automatically assumed you travel dates are for 2002.

This is due to the fact that the maximum validity of an airline ticket is ONE YEAR from the date of issue or first outbound travel which ever comes last. (Some airline tickets may be 3 months, 6 months etc, 14 days, 2 days etc.)