Why battery replacement is older than my laptop?

Hello,

Three days ago I bought an ifixit battery replacement for my MacBook through Amazon. I replaced the battery and followed all the instructions ifixit provides (Battery Calibration, SMC reset, etc). Yet, the battery drops from 42% to 7%. Then, the laptop suddenly shuts down although is 92% charged. Finally, I noticed that the battery I received is older than my laptop. The battery was manufactured on 2011-01-03. I am thinking to return the battery and buy it from a different company unless there is a satisfactory answer.

Thanks for your support.