Confusion over what is the Start date of current visa

Hello,

I am applying for a new Tier 2 visa as i am switching employers. In the application form, one of the question is: What is the start date of your current visa or leave to remain?

Now my confusion is as follows:

1) Is the start date of my current Tier 2 visa the same as the date of issue mentioned on my BRP? (for example, my BRP states 27th Nov 2014, so will this be the start date of my current visa)?
2) the letter stating that my visa was approved was dated 16th November 2014. Should i use this date as the start date?
3) the cos date says my starting work date was 16th Jan 2015 (note- i had a Post Study Work Visa valid until until 15th Jan and i switched from that to a Tier 2). So should i state my cos date of 16th jan 2015 as start of my current visa?

Any guidance or help in this matter will be greatly appreciated.

Under current Visa Status you will put your current BRP start date, end date,Yes I haveBRP, BRP number and NI number. That's what I put when did my employer switch application. Hope this helps.

Issue date of your BRP