It may be easier, rather than remembering to set such things the day before (If I have that correct), to change the method of postponing a race.
We currently have to do this as stated above, which may lead to confusion to some hosts, whom might set such a day early or day late.
I propose a calendar grid method. In this method, you would press the postpone race button, then choose the dates by dragging your finger or clicked mouse over the chosen dates for postponements. This system would also allow for multiple postponements in one go.
This system would make it easier to plan postponements for Christmas and other important events around the world.