Today (Saturday January 23), from 2-6pm Eastern time
There is autoplay video there currently with a full explanation, and you can follow more details by checking out the #hhh hashtag on twitter.
I've donated a Tuckerization from one of my next works (your choice). For those who don't know, a Tuckerization means you get to have a character named after you -- or you can give me a name of your choice instead, whatever you like. It does have to work reasonably well given the period and setting of the work, but I have a bunch to choose from so I am fairly sure I can handle virtually any name short of Princess Murgatroyd Sparklepony, and if it came to that, I might write a story AROUND the name. *grins*