Of mixed hatch dates, in the same 'bator. I use post it notes on the door of my GQF, set date, candle date, day 18, and hatch date. If I move the tray the note follows on the door, and if there is 2 different hatches in one tray its the info is on 2 notes, plus i put a no. in each set so if the tray get turned around I know which is which.