Confusion about application date

[londonukguy]

Hi Inapplied spouse visa and have confusion about exact application date
Online application 26/04/2017
Biometrics given.11/05/2017
Application confirmation mail received on Saturday 20/05/2017
Documents received by Shefield office.23/05/2017
Documents received back.14/06/2017
My question is from which date should I consider application date?
Online date
Biometrics date
Confirmation email date
Or documents reached to Home office date??
Thanks in advance for reply

[SimonS]

It's the biometrics date.