Regular SAS Gift Cards/vouchers are valid for one year.
Travel Credit Vouchers for flights affected by CoVID-19:
If your flight was canceled due to COVID-19 and you received a travel credit voucher as a refund it is valid for 1 year from the date of issue. Any value remaining when the voucher expires is refundable.
If you received a travel credit voucher for a booking you chose to cancel or postpone yourself, because of COVID-19, it is valid for 1 year from the date of issue. It is non-refundable.
If you applied and received a voucher before April 22, the old limitation of 30 November will be removed, and your voucher will automatically have the new validity of 1 year.