If your child is potty training during the day this may not mean they are automatically trained to get through the night. It could take up to two years for your child to stay completely dry at night time. Continue to use nappies to start with and then move to potty training pants. Pop your child on the potty just before bedtime and as soon as they wake. However, you may want to invest in a waterproof ﬁtted mattress protector to shield their mattress of any accidents.