esphome-docs/components/time.rst
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.. _time:
Time
====
.. seo::
:description: Instructions for setting up real time clock sources in ESPHome like network based time.
:image: clock-outline.png
:keywords: NTP, SNTP, RTC
The ``time`` component allows you to set up real time clock time sources for ESPHome.
You can then get the current time in :ref:`lambdas <config-lambda>`.
Currently only sntp (internet-based) and homeassistant time sources are supported.
Home Assistant Time Source
--------------------------
The preferred way to get time in ESPHome is using Home Assistant.
With the ``homeassistant`` time platform, the :doc:`native API </components/api>` connection
to Home Assistant will be used to periodically synchronize the current time.
.. code-block:: yaml
# Example configuration entry
time:
- platform: homeassistant
id: homeassistant_time
Configuration variables:
- **id** (*Optional*, :ref:`config-id`): Specify the ID of the time for use in lambdas.
- **timezone** (*Optional*, string): Manually tell ESPHome what timezone to use with `this format
<https://www.gnu.org/software/libc/manual/html_node/TZ-Variable.html>`__ (warning: the format is quite complicated)
or the simpler `TZ database name <https://en.wikipedia.org/wiki/List_of_tz_database_time_zones>`__ in the form
<Region>/<City>. ESPHome tries to automatically infer the timezone string based on the timezone of the computer
that is running ESPHome, but this might not always be accurate.
- **on_time** (*Optional*, :ref:`Automation <automation>`): Automation to run at specific intervals using
a cron-like syntax. See :ref:`time-on_time`.
SNTP Configuration
------------------
.. code-block:: yaml
# Example configuration entry
time:
- platform: sntp
id: sntp_time
Configuration variables:
- **id** (*Optional*, :ref:`config-id`): Specify the ID of the time for use in lambdas.
- **timezone** (*Optional*, string): Manually tell ESPHome what timezone to use with `this format
<https://www.gnu.org/software/libc/manual/html_node/TZ-Variable.html>`__ (warning: the
format is quite complicated) or the simpler `TZ database name <https://en.wikipedia.org/wiki/List_of_tz_database_time_zones>`__
in the form <Region>/<City>.
ESPHome tries to automatically infer the timezone string based on the timezone of the computer that is running
ESPHome, but this might not always be accurate.
- **servers** (*Optional*, list of strings): Choose up to 3 NTP servers that are used for the clock source.
Defaults to ``0.pool.ntp.org``, ``1.pool.ntp.org`` and ``2.pool.ntp.org``
- **on_time** (*Optional*, :ref:`Automation <automation>`): Automation to run at specific intervals using
a cron-like syntax. See :ref:`time-on_time`.
Use In Lambdas
--------------
To get the current local time with the timezone applied
in :ref:`lambdas <config-lambda>`, just call the ``.now()`` method like so:
.. code-block:: cpp
auto time = id(sntp_time).now();
Alternatively, you can use ``.utcnow()`` to get the current UTC time.
The returned object can either be used directly to get the current minute, hour, ... as numbers or a string can be
created based on a given format. If you want to get the current time attributes, you have these fields
==================== ======================================== ======================================== ====================
**Name** **Meaning** **Range (inclusive)** **Example**
-------------------- ---------------------------------------- ---------------------------------------- --------------------
``.second`` Seconds after the minute [0-60] (generally [0-59], 42
extra range is to accommodate leap
seconds.)
-------------------- ---------------------------------------- ---------------------------------------- --------------------
``.minute`` Minutes after the hour [0-59] 31
-------------------- ---------------------------------------- ---------------------------------------- --------------------
``.hour`` Hours since midnight [0-23] 16
-------------------- ---------------------------------------- ---------------------------------------- --------------------
``.day_of_week`` Day of the week, sunday=1 [1-7] 7 (saturday)
-------------------- ---------------------------------------- ---------------------------------------- --------------------
``.day_of_month`` Day of the month [1-31] 18
-------------------- ---------------------------------------- ---------------------------------------- --------------------
``.day_of_year`` Day of the year [1-366] 231
-------------------- ---------------------------------------- ---------------------------------------- --------------------
``.month`` Month, january=1 [1-12] 8 (august)
-------------------- ---------------------------------------- ---------------------------------------- --------------------
``.year`` Year since 0 A.C. [1970-∞[ 2018
-------------------- ---------------------------------------- ---------------------------------------- --------------------
``.is_dst`` Is daylight savings time false, true true
-------------------- ---------------------------------------- ---------------------------------------- --------------------
``.time`` Unix epoch time (seconds since UTC [-2147483648 - 2147483647] (negative 1534606002
Midnight January 1, 1970) values for time past January 19th 2038)
-------------------- ---------------------------------------- ---------------------------------------- --------------------
``.is_valid()`` Basic check if the time is valid false, true true
(i.e. not January 1st 1970)
==================== ======================================== ======================================== ====================
.. note::
Before the ESP has connected to the internet and can get the current time the date will be January 1st 1970. So
make sure to check if ``.is_valid()`` evaluates to ``true`` before triggering any action.
.. _strftime:
strftime
^^^^^^^^
The second way to use the time object is to directly transform it into a string like ``2018-08-16 16:31``.
This is directly done using C's `strftime <http://www.cplusplus.com/reference/ctime/strftime/>`__ function which
allows for a lot of flexibility.
.. code-block:: cpp
# For example, in a display object
it.strftime(0, 0, id(font), "%Y-%m-%d %H:%M", id(time).now());
The strftime will parse the format string (here ``"%Y-%m-%d %H:%M"``) and match anything beginning with
a percent sign ``%`` and a letter corresponding to one of the below formatting options and replace it
with the current time representation of that format option.
============= ============================================================== =========================
**Directive** **Meaning** **Example**
------------- -------------------------------------------------------------- -------------------------
``%a`` Abbreviated **weekday** name Sat
------------- -------------------------------------------------------------- -------------------------
``%A`` Full **weekday** name Saturday
------------- -------------------------------------------------------------- -------------------------
``%w`` **Weekday** as decimal number, where 0 is Sunday and 6 6
is Saturday
------------- -------------------------------------------------------------- -------------------------
``%d`` **Day of month** as zero-padded decimal number 01, 02, ..., 31
------------- -------------------------------------------------------------- -------------------------
``%b`` Abbreviated **month** name Aug
------------- -------------------------------------------------------------- -------------------------
``%B`` Full **month** name August
------------- -------------------------------------------------------------- -------------------------
``%m`` **Month** as zero-padded decimal number 01, 02, ..., 12
------------- -------------------------------------------------------------- -------------------------
``%y`` **Year** without century as a zero-padded decimal number 00, 01, ..., 99
------------- -------------------------------------------------------------- -------------------------
``%Y`` **Year** with century as a decimal number 2018
------------- -------------------------------------------------------------- -------------------------
``%H`` **Hour** (24-hour clock) as a zero-padded decimal number 00, 01, ..., 23
------------- -------------------------------------------------------------- -------------------------
``%I`` **Hour** (12-hour clock) as a zero-padded decimal number 00, 01, ..., 12
------------- -------------------------------------------------------------- -------------------------
``%p`` **AM or PM** designation AM, PM
------------- -------------------------------------------------------------- -------------------------
``%M`` **Minute** as a zero-padded decimal number 00, 01, ..., 59
------------- -------------------------------------------------------------- -------------------------
``%S`` **Second** as a zero-padded decimal number 00, 01, ..., 59
------------- -------------------------------------------------------------- -------------------------
``%j`` **Day of year** as a zero-padded decimal number 001, 002, ..., 366
------------- -------------------------------------------------------------- -------------------------
``%U`` **Week number of year** (Sunday as the first day of the week) 00, 01, ..., 53
as a zero-padded decimal number. All days in a new year
preceding the first Sunday are considered to be in week 0.
------------- -------------------------------------------------------------- -------------------------
``%W`` **Week number of year** (Monday as the first day of the week) 00, 01, ..., 53
as a zero-padded decimal number. All days in a new year
preceding the first Monday are considered to be in week 0.
------------- -------------------------------------------------------------- -------------------------
``%c`` **Date and time** representation Sat Aug 18 16:31:42 2018
------------- -------------------------------------------------------------- -------------------------
``%x`` **Date** representation 08/18/18
------------- -------------------------------------------------------------- -------------------------
``%X`` **Time** representation 16:31:42
------------- -------------------------------------------------------------- -------------------------
``%%`` A literal ``%`` character %
============= ============================================================== =========================
.. _time-on_time:
``on_time``
-----------
This powerful automation can be used to run automations at specific intervals at
specific times of day. The syntax is a subset of the `crontab <https://crontab.guru/>`__ syntax.
There are two ways to specify time intervals: Either with using the ``seconds:``, ``minutes:``, ...
keys as seen below or using a cron expression like ``* /5 * * * *``.
Basically, the automation engine looks at your configured time schedule every second and
evaluates if the automation should run.
.. code-block:: yaml
time:
- platform: sntp
# ...
on_time:
# Every 5 minutes
- seconds: 0
minutes: /5
then:
- switch.toggle: my_switch
# Every morning on weekdays
- seconds: 0
minutes: 30
hours: 7
days_of_week: MON-FRI
then:
- light.turn_on: my_light
# Cron syntax, trigger every 5 minutes
- cron: '* /5 * * * *'
then:
- switch.toggle: my_switch
Configuration variables:
- **seconds** (*Optional*, string): Specify for which seconds of the minute the automation will trigger.
Defaults to ``*`` (all seconds). Range is from 0 to 59.
- **minutes** (*Optional*, string): Specify for which minutes of the hour the automation will trigger.
Defaults to ``*`` (all minutes). Range is from 0 to 59.
- **hours** (*Optional*, string): Specify for which hours of the day the automation will trigger.
Defaults to ``*`` (all hours). Range is from 0 to 23.
- **days_of_month** (*Optional*, string): Specify for which days of the month the automation will trigger.
Defaults to ``*`` (all hours). Range is from 1 to 31.
- **months** (*Optional*, string): Specify for which months of the year to trigger.
Defaults to ``*`` (all months). The month names JAN to DEC are automatically substituted.
Range is from 1 (January) to 12 (December).
- **days_of_week** (*Optional*, string): Specify for which days of the week to trigger.
Defaults to ``*`` (all days). The names SUN to SAT are automatically substituted.
Range is from 1 (Sunday) to 7 (Saturday).
- **cron** (*Optional*, string): Alternatively, you can specify a whole cron expression like
``* /5 * * * *``. Please note years and some special characters like ``L``, ``#`` are currently not supported.
- See :ref:`Automation <automation>`.
In the ``seconds:``, ``minutes:``, ... fields you can use the following operators:
- .. code-block:: yaml
seconds: 0
An integer like ``0`` or ``30`` will make the automation only trigger if the current
second is **exactly** 0 or 30, respectively.
- .. code-block:: yaml
seconds: 0,30,45
You can combine multiple expressions with the ``,`` operator. This operator makes it so that
if either one of the expressions separated by a comma holds true, the automation will trigger.
For example ``0,30,45`` will trigger if the current second is either ``0`` or ``30`` or ``45``.
- .. code-block:: yaml
days_of_week: 2-6
# same as
days_of_week: MON-FRI
# same as
days_of_week: 2,3,4,5,6
# same as
days_of_week: MON,TUE,WED,THU,FRI
The ``-`` (hyphen) operator can be used to create a range of values and is shorthand for listing all
values with the ``,`` operator.
- .. code-block:: yaml
# every 5 minutes
seconds: 0
minutes: /5
# every timestamp where the minute is 5,15,25,...
seconds: 0
minutes: 5/10
The ``/`` operator can be used to create a step value. For example ``/5`` for ``minutes:`` makes an
automation trigger only when the minute of the hour is 0, or 5, 10, 15, ... The value in front of the
``/`` specifies the offset with which the step is applied.
- .. code-block:: yaml
# Every minute
seconds: 0
minutes: '*'
Lastly, the ``*`` operator matches every number. In the example above, ``*`` could for example be substituted
with ``0-59``.
.. warning::
Please note the following automation would trigger for each second in the minutes 0,5,10,15 and not
once per 5 minutes as the seconds variable is not set:
.. code-block:: yaml
time:
- platform: sntp
# ...
on_time:
- minutes: /5
then:
- switch.toggle: my_switch
See Also
--------
- :apiref:`time/rtc_component.h`
- :ghedit:`Edit`