Huh, had to look that one up! I have never heard of it before. A truly worthy holiday yes, I agree.
The UK doesn't have a day to celebrate the abolishing of slavery. We did it on 1st August 1834. The British Empire then set about abolishing the world wide slave trade by force using the Royal Navy. It is something our empire can be really proud of and frankly we should celbrate the 1st of August but it is like our country is ashamed of our imperial past. Yes we did some bad stuff but on balance the empire did a lot more good than bad.