How to store breastmilk?

Hi there, breastfeeding/pumping mama’s…

If you have stored breastmilk in a regular freezer since January, and you just bought a deep freezer and moved it all to the deep freezer is that same milk now good for 6-12 months or is that milk only good for 3-6 months since that is where it has been stored since initially expressed? Help, confused