Reconfirmation of your intention to travel is highly recommended. This should be done no later than 72 hours before departure and also as you arrive at the final or a transit point of your travel where you are going to stop, you should confirm your further flight at an agency or a representative office no less than 72 hours, 96 hours for the USA, in advance—this is a rule for the international airlines flights. Otherwise your reservation may be cancelled.

Some carriers no longer require reconfirmation of flights however they do recommend that you contact the carrier on the day of departure to verify times.