---
name: "lsclocks"
section: "1"
platform: "linux"
package: "util-linux"
version: "2.42.4-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/lsclocks"
---

# lsclocks(1)

display system clocks

## NAME

lsclocks - display system clocks

## SYNOPSIS

**lsclocks** \[option\]

## DESCRIPTION

**lsclocks** is a simple command to display system clocks.

It allows to display information like current time and resolution of clocks. Different kinds of clocks are supported.

• POSIX clocks: **CLOCK\_MONOTONIC**, **CLOCK\_REALTIME**, **CLOCK\_BOOTTIME**, etc.

• CPU clocks: [**clock\_getcpuclockid**(3)](/clock_getcpuclockid/3.md).

• PTP clocks: **/dev/ptp0**.

• RTC clocks: **/dev/rtc0**.

• Auxiliary clocks: **CLOCK\_AUX0**, **CLOCK\_AUX1**, etc.

## OPTIONS

- **-J**, **--json**

  Use JSON output format.

- **-n**, **--noheadings**

  Don’t print headings.

- **-o**, **--output** *list*

  Specify which output columns to print. See the **OUTPUT COLUMNS** section for details of available columns.

- **--output-all**

  Output all columns.

- **-r**, **--raw**

  Use raw output format.

- **-t**, **--time** *clock*

  Show current time of one specific clock.

- **--no-discover-dynamic**

  Do not try to discover dynamic clocks.

- **-d**, **--dynamic-clock** *path*

  Also display specified dynamic clock. Can be specified multiple times.

- **--no-discover-rtc**

  Do not try to discover RTCs.

- **-x**, **--rtc** *path*

  Also display specified RTC. Can be specified multiple times.

- **-c**, **--cpu-clock** *pid*

  Also display CPU clock of specified process. Can be specified multiple times.

- **-h**, **--help**

  Display help text and exit.

- **-V**, **--version**

  Display version and exit.

## ENVIRONMENT

LSCLOCKS\_COLUMNS=

Specifies a comma-separated list of output columns to print. All columns listed in **OUTPUT COLUMNS** can be used.

**LIBSMARTCOLS\_DEBUG**=all

enables libsmartcols debug output.

**LIBSMARTCOLS\_DEBUG\_PADDING**=on

use visible padding characters.

**LIBSMARTCOLS\_JSON**=compact\|lines

Controls JSON output format when using **--json**. Supported values are **compact** for JSON output with minimal whitespace, and **lines** for JSON Lines format (one JSON object per line). If unset or set to any other value, pretty-printed JSON is used.

## OUTPUT COLUMNS

Each column has a type. Types are surround by \< and \>.

TYPE \<`string`\>

Clock type.

ID \<`number`\>

Numeric clock ID.

CLOCK \<`string`\>

Name in the form **CLOCK\_**

NAME \<`string`\>

Shorter, easier to read name.

TIME \<`number`\>

Current clock timestamp as returned by [**clock\_gettime**(2)](/clock_gettime/2.md).

ISO\_TIME \<`string`\>

ISO8601 formatted version of **TIME**.

RESOL\_RAW \<`number`\>

Clock resolution as returned by [**clock\_getres**(2)](/clock_getres/2.md).

RESOL \<`number`\>

Human readable version of **RESOL\_RAW**.

REL\_TIME \<`string`\>

**TIME** time formatted as time range.

NS\_OFFSET \<`number`\>

Offset of the current namespace to the parent namespace as read from **/proc/self/timens\_offsets**.

## AUTHORS

*Thomas Weißschuh* \<thomas@t-8ch.de\>

## SEE ALSO

[**clock\_getres**(2)](/clock_getres/2.md) [**clock\_gettime**(2)](/clock_gettime/2.md)

## REPORTING BUGS

For bug reports, use the *issue tracker* \<https://github.com/util-linux/util-linux/issues\>.

## AVAILABILITY

The **lsclocks** command is part of the util-linux package which can be downloaded from *Linux Kernel Archive* \<https://www.kernel.org/pub/linux/utils/util-linux/\>.