Tier 2 (General) 28 days calculation for ILR

[Jigishasoni]

Hi

My query is which date shall I consider for ILR,

I have been working for a company since January 2010 - when I started working I was tier-4 student dependent. my visa was valid till 31/12/2011. On 15th August 2011 my employer issued me COS - tier-2 general with
work start date 16/08/2011 till
work end date 15/08/2013.( 2 years) -
I applied for This visa on 17/08/2011 - I got letter on 13/10/2011 - saying my application has been now approved.
BRP Issued on 14/10/2011 - valid till 29/08/2013.

in July 2013 my company gave me 2nd COS for extension with
work date - 16/08/2013 to 15/08/2016 (3 years)
I applied for extension & got FLR - till 29/08/2016 - which is 14 days plus of my COS end date - 15/08/2016

Now the question is Which date shall I consider for ILR to calculate 5 years in tier-2- the date I have been given COS - which is 16/08/2011 (work start date) or 13/10/2011 on which I received letter saying my application has been now approved.

(I have been working for the same company since Jan-2010 till date - there is no break)

can anyone help me to decide on dates.

Thanks you in advance

[ratapita]

It would be the date on the letter , which first announced that your have been granted a Tier 2 General visa.