[arch-general] Dual boot issue, windows doesn't show up on grub

[Ralf Mardorf]

On Wed, 26 Jul 2017 02:39:27 -0500, David C. Rankin wrote:
>If you are allowing systemd-boot, or grub, or syslinux to
>choose the OS, what is setting the hwclock appropriately between
>differing OS boots?

Hi,

the bootloader has got nothing to do with the way Windows or Linux does
handle the hardware clock. You have to chose for each operating
system's install, Windows, Linux A, Linux B, Linux n, BSD etc. how to
handle the time. IOW you need to set it for each install. It's your
decision what you chose.

For good reasons it's recommended to chose UTC.

[rocketmouse at archlinux ~]$ timedatectl | tail -6
Warning: The system is configured to read the RTC time in the local
time zone. This mode can not be fully supported. It will create various
problems with time zone changes and daylight saving time adjustments.
The RTC time is never updated, it relies on external facilities to
maintain it. If at all possible, use RTC in UTC by calling 'timedatectl
set-local-rtc 0'.

I'm using Linux only, no Windows, BSD etc., my settings are "freakish".
Note, I don't recommend to use the same settings as I'm using.

To avoid issues the time should be corrected gradually, if the clock is
set back, an old file quasi could be newer than a new file, which could
cause issues. IOW using local time always could cause trouble, at
least when switching from/to daylight saving time.

Please, read the Wiki https://wiki.archlinux.org/index.php/time .

Regards,
Ralf