How manufacture Date of iphone Battery is read

[OUZIEL]

Hello
In Idevicediagnosctics of battery get this

I Want to know how to read the Manufacture Date of a iphone Battery
in my example the date is : D915
Batterie serial : F5D9153QCETCL6SHJ

with 3UTolls software the date is : 4/10/2019
How the date is coded