Timing belt replacement duration

I am attempting my first timing belt replacement and interested in what people think it will take me to complete the repair. It depends on loads of factors so here is a little info to help color your estimate. I am a marine engineer so I have worked on many diesel engines but usually with connecting rods as big as I am (6 ft), cylinders with 5ft diameters, and you can stand inside the crank case (I have a picture of that somewhere). I am doing this on my 2006 BRM engine, Blauparts parts kit and their special timing belt tools. I have read chittychittybangbang's articles twice for this repair too and it seems straight forward. I will be doing it at my friend's shop where I have access to a lift, air tools, torque wrenchs, engine lifting beam and a helping hand when I need it. I am not trying to race through this, I will be thorough and methodical in my work but I just am not sure if its going to take me three days or four hours. Oh, I guess i should say oil changes take me about 20-30 minuters and changing my brake pads is usually an hour from start to clean up.

Another reason I want to know is because I will be at my friends shop at 3 ish this afternoon and he said he wants to go home at 9 and I am not sure if I can finish it tonight in the 6 ish hours I have. I dont want it to go over into tomorrow morning but if it must I want to mentally prepare to ask my wife to come pick me up!

Thanks for your help with estimating.

Byron