We have a cart of Macbook Pros with Yosemite 10.10.5 installed on them. Our school network uses 802.1x for authentication to the WiFi, but when these laptops are put in their carts and left to sit for a long time, the clock will drift off, by hours.
So when a user takes the laptop out of the cart, and tries to login in with their network account, they are not able to because the clock has drifted too far out of sync with the server. But, the clock can't pull down the correct time from the ntp server because it has no internet connection.
This has happened to multiple laptops multiple times, but it only seems to be when they are sitting for extended periods of time, though they are connected to power the entire time.
Does anyone have an idea of what would cause the clock to get so out of sync?