My Nintendo is the loyalty program that was set up at the end of March to take the place of the now-defunct Club Nintendo. Users can earn Gold Points by purchasing games off of the 3DS or Wii U eShop. Platinum Points are earned by completing specific missions, such as logging into Miiverse every week or playing Miitomo.
Prior to today, both the Gold Points and the Platinum Points expired 6 months after the user collected them. This is still the case for the Platinum Points. However, Gold Points earned today or later are now valid for 12 months after they have been collected. This gives users twice as long to spend the Gold Points that have been earned.
As always, the oldest points are always spent first when used to redeem for an item. Users can see the amount of points and the history of when they were earned or spent by checking out their account on My Nintendo.
[Source: My Nintendo]