Also affected by the policy of New Zealand, Philippines, the United States, Singapore, Indonesia and other countries, passengers who are unable to enter normal passenger flights within the time limit of purchase can be rescheduled free of charge within the validity period of the ticket. AIR China...
2021. Beyond then, you'll be able to "upgrade" these tickets to standard economy for a nonrefundable fee and then cancel your ticket. Keep in mind that you're liable for any fare difference.