lsclocks - Man Page

display system clocks


lsclocks [option]


lsclocks is a simple command to display system clocks.

It allows to display information like current time and resolution of clocks like CLOCK_MONOTONIC, CLOCK_REALTIME and CLOCK_BOOTTIME.


-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 columns.

-r,  --raw

Use raw output format.

-r, --time clock

Show current time of one specific clock.


Do not try to discover dynamic clocks.

-d,  --dynamic-clock path

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


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

Print version and exit.

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().

ISO_TIME <string>

ISO8601 formatted version of TIME.

RESOL_RAW <number>

Clock resolution as returned by clock_getres(2).

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.


Thomas Weißschuh

See Also

clock_getres(2) clock_gettime(2)

Reporting Bugs

For bug reports, use the issue tracker at


The lsclocks command is part of the util-linux package which can be downloaded from Linux Kernel Archive.


2024-03-20 util-linux 2.40