How do you show that you can remember?
You need to be able recall a decision in your own words at the time it needs to be remembered.
For how long do you need to remember?
That depends on the type of decision to be made:
Example: To decide about whether to have an operation/treatment
You would need to be able to remember until as close to the operation/treatment is being performed
Example: To take your blood
You would need to remember just for the period of time that the blood is taken
Example: To decide about moving into a care home
You would need to be able to remember as close to moving into the care home as possible
Example: To sign a tenancy agreement
You would need to remember for the period of time that the tenancy is in place