How to set the countdown to the college entrance examination on the computer desktop

How to set the countdown to the college entrance examination on the computer desktop;

Open computer notes, turn on desktop embedding and prohibit moving forms.

Then open the display of the remaining expiration time in the basic settings.

Then, you can add notes to the task, and then click the reminder button below to set a reasonable time reminder for it.

You can then display the countdown time of the task.