Reroofing

Sorry, I've lots of questions but even one answer would be appreciated! How long does it roughly take to reslate a two bedroom midterraced house? How quickly can work start? Do you need to be home when the work is going on? Would the roofers also deal with guttering? I've got cast iron gutters that need resealing at the joints and painting if they're in a condition to be saved and not sure if roofers would do this or someone else. Thanks in advanced.