Adrian wrote:When the OS is connected to the network it gets the correct time from the ntp servers, however when you reboot it has to rely on BIOS clock, if there's a difference between BIOS clock and the correct time...
This sounds strange. If the OS relies on the BIOS clock alone then the BIOS clock is the correct and only time available. My feeling is that Debian/Ubuntu has made a mess of this. Since when became ntp involved in the boot process...
Not wanting to create an argument because I think some of the best people in the Linux sphere are behind MX Linux and it's a saner OS than pretty much everything else out there. Still I want to say that it wasn't always like this. Ubuntu shipped without ntp for a long time. I think the last Ubuntu LTS release without ntp installed by default was Ubuntu 12.04 (April 2012).
There weren't boot errors related to time (Upstart). What could happen (still can) is if your time is incorrect (more than an hour generally) your DHCP Internet connection will fail to renew. But a BIOS clock is just a normal battery operated clock. It will keep time until the battery dies. For dual-booters the general advice was to let Windows handle clock sync.
I can't remember that I changed Ubuntu to local time in those days, but maybe I did. I didn't change Windows. I prefer local time because when I look at the clock in the BIOS I can easily see if it is correct or not.
The recent obsession with time in Linux is something new. From a support perspective I can understand the advantage of knowing that users have correct time. Just like MX<3 writes I also worry about boot and shutdown BIOS modifications that can wear out integrated flash over time. If there is a reason to worry, I don't know.