this is the case, goal : perform an experiment with 4 treatments. wish to run each treatment once in the morning, between 9:00 and 12:00. and once in the afternoon, between 1:00 and 4:00. all four treatments in the morning followed by all four treatments in the afternoon. and perform the test for 4 consecutive days. Now, days, order of run in mornings or evenings , as well as morning or evening tests seem nuisance factors. so I came to graeco. but each cell of graeco table shows the run of experiment for treatment A with blocks b.row , b.col and a greek letter . right. in this case, two of nuisances are time, so it can not be a run at like 9 am and simoultanously at 2 pm. what do you suggest ? what kind of a design could this be?