Changing of the clock time is also associated with "check the batteries in your smoke and Carbron Monoxide detectors." I'd also like to suggest that people using glucose meters use the date to remind themselves (parents would do it for their kids) to get their meters checked.
Our daughter almost died in 2007 from a massive DKA incident because it turned out that her meter wasn't registering correctly. Unfortunately, we knew nothing about this until after she had to be intubated, etc.
When she recovered, we all (parents, doctors, etc.) started reading her the riot act about not taking care of herself even though she insisted she was. When she suggested maybe her meter was broken we thought she was just trying to pass blame for not doing what she should. I thought I'd call her bluff and before she was released from the hospital I brought her meter in and had it checked against the hospital's. Her meter read almost 40 points lower than what the hospital meter read. Her endocrinologists (who was one of the ones that thought she just wasn't taking care of herself) apologized to her and informed us that it was as if she wasn't getting any insulin at all (despite her normal daily doses, etc.).
So get those meters checked!! I wouldn't want any parent or diabetic to have to go through what we did.