You can use a Macbook for about 5 years before wanting/needing to change. If you spend $200 a year on disposable computers, there’s really not much of a difference on the price. Also, you don’t mention software at all. As you said, it’s just a portal to the web, but as soon as you need something other than a brower,…

It’s very easy to prove/disprove if this is really the cause: just set the date to somewhere near 1970 (1971 should work as well). I don’t think this is the cause, though; I bet it’s something to do with a division by zero. But using the current date as a divisor is not common, so... perhaps something in the system’s…