August 1st 1834 was the commencement date of the The Slavery Abolition Act 1833. I think this date should be honoured as an annual bank holiday, to be observed on August 1st of each year (if a weekday), or the first weekday after August 1st.
You may be interested in these active petitions
In the 2011 Census, 3% of the UK population was black - which would be over 2m people today.
For those of us whose families originate from former colonies/the commonwealth, our nations celebrate their independence day for the UK, however the UK should celebrate the day we were rightly given back our freedom.