{
    "mode": "info",
    "parameter": "RTCWAKE",
    "section": "",
    "url": "https://www.chedong.com/phpMan.php/info/RTCWAKE/json",
    "generated": "2026-07-05T13:00:46Z",
    "synopsis": "rtcwake [options] [-d device] [-m standbymode] {-s seconds|-t timet}",
    "sections": {
        "NAME": {
            "content": "rtcwake - enter a system sleep state until specified wakeup time\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "rtcwake [options] [-d device] [-m standbymode] {-s seconds|-t timet}\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "This program is used to enter a system sleep state and to automatically\nwake from it at a specified time.\n\nThis uses cross-platform Linux interfaces to enter a system sleep\nstate, and leave it no later than a specified time. It uses any RTC\nframework driver that supports standard driver model wakeup flags.\n\nThis is normally used like the old apmsleep utility, to wake from a\nsuspend state like ACPI S1 (standby) or S3 (suspend-to-RAM). Most\nplatforms can implement those without analogues of BIOS, APM, or ACPI.\n\nOn some systems, this can also be used like nvram-wakeup, waking from\nstates like ACPI S4 (suspend to disk). Not all systems have persistent\nmedia that are appropriate for such suspend modes.\n\nNote that alarm functionality depends on hardware; not every RTC is\nable to setup an alarm up to 24 hours in the future.\n\nThe suspend setup may be interrupted by active hardware; for example\nwireless USB input devices that continue to send events for some\nfraction of a second after the return key is pressed. rtcwake tries to\navoid this problem and it waits to terminal to settle down before\nentering a system sleep.\n",
            "subsections": []
        },
        "OPTIONS": {
            "content": "-A, --adjfile file\nSpecify an alternative path to the adjust file.\n",
            "subsections": [
                {
                    "name": "-a, --auto",
                    "content": "Read the clock mode (whether the hardware clock is set to UTC or\nlocal time) from the adjtime file, where hwclock(8) stores that\ninformation. This is the default.\n\n--date timestamp\nSet the wakeup time to the value of the timestamp. Format of the\ntimestamp can be any of the following:\n\n+--------------------+---------------------------+\n|                    |                           |\n|YYYYMMDDhhmmss      |                           |\n+--------------------+---------------------------+\n|                    |                           |\n|YYYY-MM-DD hh:mm:ss |                           |\n+--------------------+---------------------------+\n|                    |                           |\n|YYYY-MM-DD hh:mm    | (seconds will be set to   |\n|                    | 00)                       |\n+--------------------+---------------------------+\n|                    |                           |\n|YYYY-MM-DD          | (time will be set to      |\n|                    | 00:00:00)                 |\n+--------------------+---------------------------+\n|                    |                           |\n|hh:mm:ss            | (date will be set to      |\n|                    | today)                    |\n+--------------------+---------------------------+\n|                    |                           |\n|hh:mm               | (date will be set to      |\n|                    | today, seconds to 00)     |\n+--------------------+---------------------------+\n|                    |                           |\n|tomorrow            | (time is set to 00:00:00) |\n+--------------------+---------------------------+\n|                    |                           |\n|+5min               |                           |\n+--------------------+---------------------------+\n\n-d, --device device\nUse the specified device instead of rtc0 as realtime clock. This\noption is only relevant if your system has more than one RTC. You\nmay specify rtc1, rtc2, ... here.\n",
                    "flag": "-a",
                    "long": "--auto"
                },
                {
                    "name": "-l, --local",
                    "content": "Assume that the hardware clock is set to local time, regardless of\nthe contents of the adjtime file.\n",
                    "flag": "-l",
                    "long": "--local"
                },
                {
                    "name": "--list-modes",
                    "content": "List available --mode option arguments.\n\n-m, --mode mode\nGo into the given standby state. Valid values for mode are:\n\nstandby\nACPI state S1. This state offers minimal, though real, power\nsavings, while providing a very low-latency transition back to\na working system. This is the default mode.\n\nfreeze\nThe processes are frozen, all the devices are suspended and all\nthe processors idled. This state is a general state that does\nnot need any platform-specific support, but it saves less power\nthan Suspend-to-RAM, because the system is still in a running\nstate. (Available since Linux 3.9.)\n\nmem\nACPI state S3 (Suspend-to-RAM). This state offers significant\npower savings as everything in the system is put into a\nlow-power state, except for memory, which is placed in\nself-refresh mode to retain its contents.\n\ndisk\nACPI state S4 (Suspend-to-disk). This state offers the greatest\npower savings, and can be used even in the absence of low-level\nplatform support for power management. This state operates\nsimilarly to Suspend-to-RAM, but includes a final step of\nwriting memory contents to disk.\n\noff\nACPI state S5 (Poweroff). This is done by calling\n'/sbin/shutdown'. Not officially supported by ACPI, but it\nusually works.\n\nno\nDon't suspend, only set the RTC wakeup time.\n\non\nDon't suspend, but read the RTC device until an alarm time\nappears. This mode is useful for debugging.\n\ndisable\nDisable a previously set alarm.\n\nshow\nPrint alarm information in format: \"alarm: off|on <time>\". The\ntime is in ctime() output format, e.g., \"alarm: on Tue Nov 16\n04:48:45 2010\".\n",
                    "long": "--list-modes"
                },
                {
                    "name": "-n, --dry-run",
                    "content": "This option does everything apart from actually setting up the\nalarm, suspending the system, or waiting for the alarm.\n\n-s, --seconds seconds\nSet the wakeup time to seconds in the future from now.\n\n-t, --time timet\nSet the wakeup time to the absolute time timet. timet is the time\nin seconds since 1970-01-01, 00:00 UTC. Use the date(1) tool to\nconvert between human-readable time and timet.\n",
                    "flag": "-n",
                    "long": "--dry-run"
                },
                {
                    "name": "-u, --utc",
                    "content": "Assume that the hardware clock is set to UTC (Universal Time\nCoordinated), regardless of the contents of the adjtime file.\n",
                    "flag": "-u",
                    "long": "--utc"
                },
                {
                    "name": "-v, --verbose",
                    "content": "Be verbose.\n",
                    "flag": "-v",
                    "long": "--verbose"
                },
                {
                    "name": "-V, --version",
                    "content": "Display version information and exit.\n",
                    "flag": "-V",
                    "long": "--version"
                },
                {
                    "name": "-h, --help",
                    "content": "Display help text and exit.\n",
                    "flag": "-h",
                    "long": "--help"
                }
            ]
        },
        "NOTES": {
            "content": "Some PC systems can't currently exit sleep states such as mem using\nonly the kernel code accessed by this driver. They need help from\nuserspace code to make the framebuffer work again.\n",
            "subsections": []
        },
        "FILES": {
            "content": "/etc/adjtime\n",
            "subsections": []
        },
        "HISTORY": {
            "content": "The program was posted several times on LKML and other lists before\nappearing in kernel commit message for Linux 2.6 in the GIT commit\n87ac84f42a7a580d0dd72ae31d6a5eb4bfe04c6d.\n",
            "subsections": []
        },
        "AUTHORS": {
            "content": "The program was written by David Brownell\n<dbrownell@users.sourceforge.net> and improved by Bernhard Walle\n<bwalle@suse.de>.\n",
            "subsections": []
        },
        "COPYRIGHT": {
            "content": "This is free software. You may redistribute copies of it under the\nterms of the GNU General Public License\n<http://www.gnu.org/licenses/gpl.html>. There is NO WARRANTY, to the\nextent permitted by law.\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "hwclock(8), date(1)\n",
            "subsections": []
        },
        "REPORTING BUGS": {
            "content": "For bug reports, use the issue tracker at\nhttps://github.com/karelzak/util-linux/issues.\n",
            "subsections": []
        },
        "AVAILABILITY": {
            "content": "The rtcwake command is part of the util-linux package which can be\ndownloaded from Linux Kernel Archive\n<https://www.kernel.org/pub/linux/utils/util-linux/>.\n\nutil-linux 2.37.2                 2021-06-02                        RTCWAKE(8)",
            "subsections": []
        }
    },
    "summary": "rtcwake - enter a system sleep state until specified wakeup time",
    "flags": [
        {
            "flag": "-a",
            "long": "--auto",
            "arg": null,
            "description": "Read the clock mode (whether the hardware clock is set to UTC or local time) from the adjtime file, where hwclock(8) stores that information. This is the default. --date timestamp Set the wakeup time to the value of the timestamp. Format of the timestamp can be any of the following: +--------------------+---------------------------+ | | | |YYYYMMDDhhmmss | | +--------------------+---------------------------+ | | | |YYYY-MM-DD hh:mm:ss | | +--------------------+---------------------------+ | | | |YYYY-MM-DD hh:mm | (seconds will be set to | | | 00) | +--------------------+---------------------------+ | | | |YYYY-MM-DD | (time will be set to | | | 00:00:00) | +--------------------+---------------------------+ | | | |hh:mm:ss | (date will be set to | | | today) | +--------------------+---------------------------+ | | | |hh:mm | (date will be set to | | | today, seconds to 00) | +--------------------+---------------------------+ | | | |tomorrow | (time is set to 00:00:00) | +--------------------+---------------------------+ | | | |+5min | | +--------------------+---------------------------+ -d, --device device Use the specified device instead of rtc0 as realtime clock. This option is only relevant if your system has more than one RTC. You may specify rtc1, rtc2, ... here."
        },
        {
            "flag": "-l",
            "long": "--local",
            "arg": null,
            "description": "Assume that the hardware clock is set to local time, regardless of the contents of the adjtime file."
        },
        {
            "flag": "",
            "long": "--list-modes",
            "arg": null,
            "description": "List available --mode option arguments. -m, --mode mode Go into the given standby state. Valid values for mode are: standby ACPI state S1. This state offers minimal, though real, power savings, while providing a very low-latency transition back to a working system. This is the default mode. freeze The processes are frozen, all the devices are suspended and all the processors idled. This state is a general state that does not need any platform-specific support, but it saves less power than Suspend-to-RAM, because the system is still in a running state. (Available since Linux 3.9.) mem ACPI state S3 (Suspend-to-RAM). This state offers significant power savings as everything in the system is put into a low-power state, except for memory, which is placed in self-refresh mode to retain its contents. disk ACPI state S4 (Suspend-to-disk). This state offers the greatest power savings, and can be used even in the absence of low-level platform support for power management. This state operates similarly to Suspend-to-RAM, but includes a final step of writing memory contents to disk. off ACPI state S5 (Poweroff). This is done by calling '/sbin/shutdown'. Not officially supported by ACPI, but it usually works. no Don't suspend, only set the RTC wakeup time. on Don't suspend, but read the RTC device until an alarm time appears. This mode is useful for debugging. disable Disable a previously set alarm. show Print alarm information in format: \"alarm: off|on <time>\". The time is in ctime() output format, e.g., \"alarm: on Tue Nov 16 04:48:45 2010\"."
        },
        {
            "flag": "-n",
            "long": "--dry-run",
            "arg": null,
            "description": "This option does everything apart from actually setting up the alarm, suspending the system, or waiting for the alarm. -s, --seconds seconds Set the wakeup time to seconds in the future from now. -t, --time timet Set the wakeup time to the absolute time timet. timet is the time in seconds since 1970-01-01, 00:00 UTC. Use the date(1) tool to convert between human-readable time and timet."
        },
        {
            "flag": "-u",
            "long": "--utc",
            "arg": null,
            "description": "Assume that the hardware clock is set to UTC (Universal Time Coordinated), regardless of the contents of the adjtime file."
        },
        {
            "flag": "-v",
            "long": "--verbose",
            "arg": null,
            "description": "Be verbose."
        },
        {
            "flag": "-V",
            "long": "--version",
            "arg": null,
            "description": "Display version information and exit."
        },
        {
            "flag": "-h",
            "long": "--help",
            "arg": null,
            "description": "Display help text and exit."
        }
    ],
    "examples": [],
    "see_also": [
        {
            "name": "hwclock",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/hwclock/8/json"
        },
        {
            "name": "date",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/date/1/json"
        }
    ]
}