zeespark sums it up, but id also say the address of where your working and any travelling times ie if a job in london first then travelling time to next job etc. the arrival time at next job and so on
also a v. brief description of what you did e.g. ' first fixed all of first floor lighting except hallway. hallway not done due to joiners blocking access'. That way if somebody ever said 'why didn't you finish the hall lighting at XYZ?' you can point to the day sheet. Well that's what I made all my lads do......... :coat