In short, they program, email each other about programming, meet to figure out what to program next, talk about programming, grab coffee so they can program longer, drink water so they can program hydrated, take naps and dream about programming and occasionally take bathroom breaks due to all the coffee and water.
Yes they are given set tasks to do and have to go into the office 9-5 to do it like any other programming job.
I don't know what your purpose for this thread was or what kind of answer you was expecting but that's about the gist of it.