---
name: "hwclock"
section: "5"
platform: "linux"
package: "initscripts"
version: "3.14-4"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/hwclock/5"
---

# hwclock(5)

settings that affect the behaviour of the hwclock init script

## NAME

hwclock - settings that affect the behaviour of the hwclock init script

## DESCRIPTION

The */etc/default/hwclock* file contains settings in POSIX format:

-

  VAR=VAL

Only one assignment is allowed per line. Comments (starting with '#') are also allowed.

## SETTINGS

The following settings can be set.

- **HCTOSYS\_DEVICE**

  The hardware clock device you want to use.  Defaults to **rtc0**. It should probably match the CONFIG\_RTC\_HCTOSYS\_DEVICE kernel config option.

  If you change this, you also need to install a custom udev rule, mirroring **/usr/lib/udev/rules.d/85-hwclock.rules**. Otherwise, the hardware clock device will be ignored during boot.

  On almost all systems, this should not be changed.

## NOTES

On systems using systemd as init, the hwclock init script is ignored.

## SEE ALSO

[**hwclock**(8)](/hwclock/8.md), [**systemd-timesyncd.service**(8)](/systemd-timesyncd.service/8.md)