Thank you so much!

For some reason it was very hard to find this info

Hi there, I've been in the UK on a 2-year Tier 5 Youth Mobility. My entry clearance vignette was valid from 5th July 2017, and I entered the UK on 12th July 2017 - does my 2 years begin from this date (12th), or from the start date on my entry clearance (5th)?. My BRP says 'valid to 5th July 2019' s...