The dressage steward will tell you if they are running ahead, on or behind time so you can adjust warm up/getting ready times if required. When returning from the dressage I will ask the SJ steward how they are running their order and if to time. If they are running to an order of numbers being written on a board you know to get your number written down as soon as you enter the warm up. If they are running 30 minutes late and running to order you know not to get back on for a while and on the same vein if running to numbers on board and you only have to make a minor tack change you can put your number down make the change and save yourself an extra workin. Finally your XC steward will give you similar information.
A lot of you reading may speak to the stewards already but it surprises me the amount of riders I see turn up at a warm up completely unaware that there is an hour delay or who work in then go up to the steward expecting to go next as it is their time to find the steward is running numbers on a board and there are 15 horses written down so they have to wait a further 20 minutes before they get to jump so over cooking their work in.