One of my colleagues decided to retire next month. We got him/her a retirement clock to display the number of days remaining before the target date. Setting today’s time was easy enough, but many people were having trouble setting the target date. The target date is the retirement date/time that the clock will countdown to.
TL;DR — hold down the Mode button for several seconds and you will get a different screen for setting the target date/time. Normally, pressing Mode button quickly let’s you change the current date/time on the clock.
Here is the PDF for the above image: countdown-clock