Daylight saving time, thoughts?

Science and Technology
61

It is just me objecting to any attempts to hide reality from the user.

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62 
# hwclock --show
2025-10-27 21:28:00.623725+11:00
# date
Mon 27 Oct 2025 21:28:06 AEDT
# date -u
Mon 27 Oct 2025 10:28:36 UTC

OK my computer is using UTC I think, , but , if i create a file

# cat > junk
lllll     
# ls -l junk
-rw-r--r-- 1 nevj nevj 6 Oct 27 21:31 junk
#

It displays its time in localtime.
So, when I use make does it look at localtime of .o files as in the ls or is that just for display and make sees UTC?

You can see why I dont trust displays fiddling with the content.
I need to know what make sees as the file creation time attribute.?

Or is my computer using localtime? I dont even know if the hwclock output is fiddled.

This is in Void. I will check another distro.
MX is the same … well at least they are consistent.

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63

IIRC, hwclock has to be in UTC timescale.

1 Like
64

That sounds sensible , you would not want the system clock jumping back or forward for DST
but


[quote="Neville Jackson, post:62, topic:12662, username:nevj"]

hwclock --show

2025-10-27 21:28:00.623725+11:00

[/quote]

21:28 is localtime ??

So does the ‘hw clock’ keep UTC, but the hwclock --show command display localtime?

I am confused

Edit:
The Arch wiki explains

but only for systemd users.

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65

This is how it does it

" Standard behavior of most operating systems is:

  • Set the system clock from the hardware clock on boot.
  • Keep accurate time of the system clock, see #Time synchronization.
  • Set the hardware clock from the system clock on shutdown."
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66

image
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67

It is strange. We have the technology to navigate a spaceship to Mars, but we can not cope with our own localtime.

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68

Dual booting Windows and Linux is a bit of a pain because Windows assumes the computer is set to local time. Linux assumes it is set to UTC time. That’s by default. Linux can be configured so it is aware the computer time is set to local time. If you don’t do this and you reboot from Windows to Linux the time changes and sometimes even the date, depending on the time of day.

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69

Can Windows be configured to assume UTC?

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70

Yes, it can. Every machine dealing with time zones can.

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71

I have always ran Gentoo using local time, have never had any issues!!!

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72

But have you ever run make for compiling a kernel or any other huge compiling job within the switching hour?

BTW, I’m also using local time; I think it’s a default habit.

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73

I think nearly everyone defaults to that.
It really makes zero differnce within one machine … except on switching night.

Sharing files around the globe may be another matter… i have never tried it in any critical manner.

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