Yes, you can still use them for your upcoming bookings before the reward expiry date, subject to the same Terms and Conditions.
Details and usage information on KrisFlyer Milestone Rewards and PPS Rewards can be found in the Rewards and vouchers tab when logged in to your KrisFlyer account on singaporeair.com.
PPS Club gift vouchers can only be used on KrisShop purchases. Find out how to redeem them here.
KrisFlyer Milestone Rewards cannot be transferred. However, you can use the 5,000 KrisFlyer Miles Redemption Discount, Short-haul Advance Upgrade and Premium Economy Advance Upgrade rewards for bookings for your redemption nominees.