That’s offset by the extra grouchyness on the flipside of the year (usally for us Northern Hemisherers to be 5 months later) 
still struggling… I need a binary for a today’s dst setting change: today dst changed.
both binaries are added to the template, but neither off them says so. the first says only if dst is active today, the second indicates tomorrow dst will change…
If only I would know if petros day counter would go down to 0, I could use that.
What am I missing here (going round and round in circles)
or, would this do that:
dst changed today: >
{% set dt = now() + timedelta(days=-1) %}
{{ now().astimezone().tzinfo != dt.astimezone().tzinfo }}
Ever wonder “why did I add this contribution” after seeing it go from a simple contribution of a few lines of YAML code to a debated project encompassing dozens of lines of code and arguments over how that code should be interpreted?
Or is it just me? 
2 Likes
nope, true.
that’s what you get when you share useful code 
here’s a bit more:
- alias: Dst change clocks
trigger:
- platform: time
at: '10:00'
- platform: time
at: '19:00'
condition:
condition: template
value_template: >
{{(trigger.now.strftime('%H:%M') == '10:00' and
state_attr('sensor.dst','dst changed today') == true) or
(trigger.now.strftime('%H:%M') == '19:00' and
state_attr('sensor.dst','dst change tomorrow') == true)}}
action:
- service: notify.system
data:
title: >
Dst {{'tomorrow' if state_attr('sensor.dst','dst change tomorrow') == true
else 'today'}}
message: >
{% set today = state_attr('sensor.dst','dst changed today') %}
{% set change = state_attr('sensor.dst','next').clock %}
{% set suffix = 's' if today == true else 'ed' %}
Daylight savings start{{suffix}} {{'today, please set all
clocks 1 hour ' + change + ' manually if necessary.' if today == false else 'tomorrow'}}
- condition: template
value_template: >
{{state_attr('sensor.dst','dst changed today') == true}}
- service: input_boolean.turn_on
entity_id: input_boolean.dst
If it helps any I was quite happy with your original code. 
The only thing I changed was I turned it into a binary sensor instead of a regular sensor so it was easier to trigger a reminder automation.
But petro’s code gave more info so I incorporated your code into his for the best of both worlds.
I’m not having any issues at all interpreting the code.
I don’t get what you are having an issue with.
that attribute will be true if “dst active” will change tomorrow otherwise it’s false (by definition a binary sensor).
So if that attribute is true you can use that to trigger a notification the day prior so you remember to set the clocks accordingly.
The “thinking” is done for you in the automation.
Here are a couple of automations to send a pushbullet notification in the morning and make an announcement at night to remind you. They are solely based on the original code in the first post except I made them binary sensors instead or non-binary:
- alias: 'Notification DST'
trigger:
- platform: state
entity_id: binary_sensor.dst_change_tomorrow
to: 'on'
action:
choose:
- conditions:
- "{{ states('binary_sensor.is_dst') == 'off' }}"
sequence:
- service: notify.pushbullet_notify
data:
message: 'DST time starts tomorrow. Set the clocks ahead tonight.'
- conditions:
- "{{ states('binary_sensor.is_dst') == 'on' }}"
sequence:
- service: notify.pushbullet_notify
data:
message: 'DST ends time tomorrow. Set clocks back tonight.'
- alias: 'TTS DST'
trigger:
- platform: time
at: '23:00:00'
action:
choose:
- conditions:
- "{{ states('binary_sensor.dst_change_tomorrow') == 'on' }}"
- "{{ states('binary_sensor.is_dst') == 'off' }}"
sequence:
- service: notify.alexa_media
data:
target:
- media_player.computer_room_dot
- media_player.kitchen_dot
- media_player.garage_dot
- media_player.basement_dot
- media_player.livingroom_dot
- media_player.sunroom_dot
data:
type: tts
message: "Daylight Savings Time starts tomorrow. Don't forget to set the clocks ahead."
- conditions:
- "{{ states('binary_sensor.dst_change_tomorrow') == 'on' }}"
- "{{ states('binary_sensor.is_dst') == 'on' }}"
sequence:
- service: notify.alexa_media
data:
target:
- media_player.computer_room_dot
- media_player.kitchen_dot
- media_player.garage_dot
- media_player.basement_dot
- media_player.livingroom_dot
- media_player.sunroom_dot
data:
type: tts
message: "Daylight Savings Time ends tomorrow. Don't forget to set the clocks back."
Indeed I seem to have failed to make that happen 
As I have been trying to bring across, I want a binary for the ‘today’ change. Because I don’t only want a headsup for tomorrows change, I also want a reminder on the day itself, to reset the clocks.
so I added the extra attribute (binary) to make that possible.
My automation does it all as far as I can see now, both for tomorrow and today. Ive edited the message to incorporate the sleep indication for case tomorrow
- alias: Dst change clocks
trigger:
- platform: time
at: '10:00'
- platform: time
at: '19:00'
condition:
condition: template
value_template: >
{{(trigger.now.strftime('%H:%M') == '10:00' and
state_attr('sensor.dst','dst changed today') == true) or
(trigger.now.strftime('%H:%M') == '19:00' and
state_attr('sensor.dst','dst change tomorrow') == true)}}
action:
- service: notify.system
data:
title: >
Dst {{'tomorrow' if state_attr('sensor.dst','dst change tomorrow') == true
else 'today'}}
message: >
{% set today = state_attr('sensor.dst','dst changed today') %}
{% set change = state_attr('sensor.dst','next').clock %}
{% set phrase = state_attr('sensor.dst','next').phrase %}
{% set suffix = 's' if today == false else 'ed' %}
Daylight savings start{{suffix}} {{'today, please set all
clocks 1 hour ' + change + ' manually if necessary.' if today == true else
'tomorrow, you will ' + phrase + ' of sleep'}}
- condition: template
value_template: >
{{state_attr('sensor.dst','dst changed today') == true}}
- service: input_boolean.turn_on
entity_id: input_boolean.dst
@petro Did you find a way to deliver the DST info for a different timezone to your local one?
Just a minor FYI - your code assumes Spring comes before Fall in your code. Not true in the southern hemisphere !
getting back to this, because the frontend representation of the timestamp device_class is somewhat peculiar:
stating ‘In 1 day’:
while in fact is is 2…
today is the 26th… so the more-info is correct on all attributes and state.
Sorry to dig up this thread.
Does anybody have a simple boolean sensor that returns TRUE during winter time and FALSE during summer time? Or vice-versa?
I use the following binary template sensor for that:
binary_sensor:
- platform: template
sensors:
sommerzeit:
friendly_name: "Sommerzeit"
icon_template: "mdi:weather-sunny"
value_template: "{{ now().timetuple().tm_isdst == 1 }}"
you beat me to it
in the new template: format:
template:
- binary_sensor:
- unique_id: zomertijd_binary
name: Zomertijd
picture: /local/season/summer.png
state: >
{{now().timetuple().tm_isdst == 1}}
- unique_id: wintertijd_binary
name: Wintertijd
picture: /local/season/winter.png
state: >
{{now().timetuple().tm_isdst == 0}}
Love you both <3
still having an issue here, because after the actual DST at 3 o’clock last night, it still shows:
the 2 top lines are ok, the 2 bottom lines aren’t. They say:
next change will take place tonight!
clock will then advance 1 hour and we loose an hour…
{% set x = ['unknown','unavailable'] %}
{% if states('sensor.daylight_savings_times') not in x %}
<img src = {{state_attr('binary_sensor.wintertijd','entity_picture')
if is_state('binary_sensor.wintertijd','on')
else state_attr('binary_sensor.zomertijd','entity_picture') }} width='80'>
**Zomertijd - Wintertijd**
DST is {{'niet actief' if state_attr('sensor.daylight_savings_times','dst_active')
== false else 'actief'}} en het is {{'Wintertijd' if is_state('binary_sensor.wintertijd','on')
else 'Zomertijd'}}.
{% set count = state_attr('sensor.daylight_savings_times','next')
.days_to_event %}
{% set datum = as_timestamp(states.sensor.daylight_savings_times.attributes.next.event,0)
|timestamp_custom('%d %B %Y',default=0) %}
De volgende wissel vindt
{%- if count == 0 %} vannacht plaats!
{%- elif count == 1 %} morgen plaats op {{datum}}.
{%- elif count == 2 %} overmorgen plaats op {{datum}}.
{%- elif count > 2 %} plaats over {{count}} dagen op {{datum}}.
{%- endif %}
De klok gaat dan 1 uur {{state_attr('sensor.daylight_savings_times','next')
.clock}} en we {{state_attr('sensor.daylight_savings_times','next').phrase}}.
{% else %} Calculating
{% endif %}
ofc, this is built upon the bigger dst template, which I now have to be:
sensor:
- unique_id: daylight_savings_times
name: Daylight savings times
device_class: timestamp
state: >
{%- set ns = namespace(previous=3,spring=none,fall=none) %}
{%- set today = strptime(states('sensor.date'),'%Y-%m-%d').astimezone().replace(hour=ns.previous) %}
{%- for i in range(365) %}
{%- set day = (today + timedelta(days=i)).astimezone() %}
{%- if ns.previous - day.hour == -1 %}
{%- set ns.spring = today + timedelta(days=i) %}
{%- elif ns.previous - day.hour == 1 %}
{%- set ns.fall = today + timedelta(days=i) %}
{%- endif %}
{%- set ns.previous = day.hour %}
{%- endfor %}
{{([ns.spring,ns.fall]|min).isoformat()}}
# {{as_timestamp([ns.spring,ns.fall]|min)|timestamp_custom('%A %-d %B %Y at %-H am')}}
icon: >
mdi:{{(now().timetuple().tm_isdst == 1)|iif('update','history')}}
attributes:
icon_color: >
{{'gold' if is_state('binary_sensor.zomertijd','on') else 'steelblue'}}
# https://pythontic.com/datetime/datetime/timetuple
dst_active: >
{{now().timetuple().tm_isdst == 1}}
dst_change_tomorrow: >
{% set dt = now() + timedelta(days=1) %}
{{now().astimezone().tzinfo != dt.astimezone().tzinfo}}
dst_changed_today: >
{% set dt = now() + timedelta(days=-1) %}
{{now().astimezone().tzinfo != dt.astimezone().tzinfo}}
next: >
{%- set ns = namespace(previous = 3,spring=none,fall=none) %}
{%- set today = strptime(states('sensor.date'),'%Y-%m-%d').astimezone().replace(hour=ns.previous) %}
{%- for i in range(365) %}
{%- set day = (today + timedelta(days=i)).astimezone() %}
{%- if ns.previous - day.hour == -1 %}
{%- set ns.spring = today + timedelta(days=i) %}
{%- elif ns.previous - day.hour == 1 %}
{%- set ns.fall = today + timedelta(days=i) %}
{%- endif %}
{%- set ns.previous = day.hour %}
{%- endfor %}
{%- set next = [ns.spring, ns.fall]|min %}
{%- set phrase = 'verliezen een uur' if next == ns.spring else 'krijgen een uur extra' %}
{%- set clock = 'vooruit' if next == ns.spring else 'terug' %}
{"spring": "{{ns.spring.isoformat()}}",
"fall": "{{ns.fall.isoformat()}}",
"event": "{{next.isoformat()}}",
"days_to_event":{{(next-today).days}},
"phrase": "{{phrase}}",
"clock":"{{clock}}"}
this is triggered per hour, but the attribute next items change per day. Meaning, if the event has happened, and it is still this day, the attributes dont change. Which is a bit of a nasty detail really. Now have to wait a full day for this to become correct again.
current output in dev tools:
- unique_id: daylight_savings_times
name: Daylight savings times
device_class: timestamp
state: >
2023-03-26T03:00:00+01:00
# Sunday 26 March 2023 at 4 am
icon: >
mdi:update
attributes:
icon_color: >
gold
# https://pythontic.com/datetime/datetime/timetuple
dst_active: >
True
dst_change_tomorrow: >
False
dst_changed_today: >
True
next: >
{"spring": "2023-03-26T03:00:00+01:00",
"fall": "2023-10-29T03:00:00+01:00",
"event": "2023-03-26T03:00:00+01:00",
"days_to_event":0,
"phrase": "verliezen een uur",
"clock":"vooruit"}
fwiw, the mentioned binary_sensors inside the other templates are:
binary_sensor:
- unique_id: zomertijd_binary
name: Zomertijd
picture: /local/season/summer.png
state: >
{{now().timetuple().tm_isdst == 1}}
- unique_id: wintertijd_binary
name: Wintertijd
picture: /local/season/winter.png
state: >
{{now().timetuple().tm_isdst == 0}}
so always spot on
after some discussion on Discord with @TheFes, decided to change the template to use today_at(), and some extra evaluating the ns.spring and ns.fall operations.
when ns.fall or ns.spring are already entered (so they are not none anymore) it will use the current value
setting the range to a bit higher than 365 allows it to pick up a next change that would falll out of that range, like it does this year … so, currently changed to:
sensor:
- unique_id: daylight_savings_times
name: Daylight savings times
device_class: timestamp
state: >
{%- set ns = namespace(previous=3,spring=none,fall=none) %}
{%- set today = today_at().astimezone().replace(hour=ns.previous) %}
{%- for i in range(500) %}
{%- set day = (today + timedelta(days=i)).astimezone() %}
{%- if ns.previous - day.hour == -1 %}
{%- set ns.spring = today + timedelta(days=i) if ns.spring is none else ns.spring %}
{%- elif ns.previous - day.hour == 1 %}
{%- set ns.fall = today + timedelta(days=i) if ns.fall is none else ns.fall %}
{%- endif %}
{%- set ns.previous = day.hour %}
{%- endfor %}
{{([ns.spring,ns.fall]|min).isoformat()}}
icon: >
mdi:{{(now().timetuple().tm_isdst == 1)|iif('update','history')}}
attributes:
icon_color: >
{{'gold' if is_state('binary_sensor.zomertijd','on') else 'steelblue'}}
# https://pythontic.com/datetime/datetime/timetuple
dst_active: >
{{now().timetuple().tm_isdst == 1}}
dst_change_tomorrow: >
{% set dt = now() + timedelta(days=1) %}
{{now().astimezone().tzinfo != dt.astimezone().tzinfo}}
dst_changed_today: >
{% set dt = now() + timedelta(days=-1) %}
{{now().astimezone().tzinfo != dt.astimezone().tzinfo}}
next: >
{%- set ns = namespace(previous=3,spring=none,fall=none) %}
{%- set today = today_at().astimezone().replace(hour=ns.previous) %}
{%- for i in range(500) %}
{%- set day = (today + timedelta(days=i)).astimezone() %}
{%- if ns.previous - day.hour == -1 %}
{%- set ns.spring = today + timedelta(days=i) if ns.spring is none else ns.spring %}
{%- elif ns.previous - day.hour == 1 %}
{%- set ns.fall = today + timedelta(days=i) if ns.fall is none else ns.fall %}
{%- endif %}
{%- set ns.previous = day.hour %}
{%- endfor %}
{%- set next = [ns.spring, ns.fall] | reject('<', now()) | min %}
{%- set result = 'verliezen een uur' if next == ns.spring else 'krijgen een uur extra' %}
{%- set motion = 'vooruit' if next == ns.spring else 'terug' %}
{"spring": "{{ns.spring.isoformat()}}",
"fall": "{{ns.fall.isoformat()}}",
"event": "{{next.isoformat()}}",
"days_to_event":{{(next-today).days}},
"result": "{{result}}",
"motion":"{{motion}}",
"phrase":"{{as_timestamp([ns.spring,ns.fall]|min)
|timestamp_custom('%A %-d %B %Y at %-H am')}}"
}
This being a rather generic approach, which is good, we might be able to make it more to the point, as the dst changes (in the EU) always take place the last Sunday in March or October.
that could reduce the number of iterations maybe? Not sure how to implement that, but it seems we only need to check 8-10 Sundays max, instead of 365 days…
coming beta 2023.4 will add some new functionality, relevant for this template, being able to ‘break’ a loop. it should allow to do:
{%- set n = now() %}
{%- set m = today_at().astimezone(utcnow().tzinfo) %}
{%- set t = n.hour - utcnow().hour + (0 if n.timetuple().tm_isdst else 1) %}
{%- set ns = namespace(spring='', autumn='') %}
{%- for i in range(1,750) %}
{%- set d1, d2 = n + timedelta(days=i-1), n + timedelta(days=i) %}
{%- set d1dst, d2dst = d1.timetuple().tm_isdst, d2.timetuple().tm_isdst %}
{%- if ns.spring and ns.autumn %}
{%- break %}
{%- else %}
{%- if d1dst > d2dst %}
{%- set ns.autumn = as_local(m + timedelta(days=i, hours=t)).isoformat() %}
{%- elif d1dst < d2dst %}
{%- set ns.spring = as_local(m + timedelta(days=i, hours=t)).isoformat() %}
{%- endif %}
{%- endif %}
{%- endfor %}
TheFes wrote that, so he’s the expert, and credits go to him (again)
1 Like
A very informative inspiring discussion. But for me just receiving a notification on the night before a DTS change, was good enough. I made this simple automation for that:
alias: DTS changes
description: Notify at 20h when DTS changes tonight
trigger:
- platform: time
at: "20:00:00"
variables:
currDST: "{{ now().timetuple().tm_isdst }}"
nextDST: "{{ (now()+timedelta(days=1)).timetuple().tm_isdst }}"
condition:
- condition: template
value_template: "{{ currDST != nextDST }}"
action:
- service: notify.notify
data:
title: |
{{ 'Wintertijd gaat in' if currDST > nextDST else 'Zomertijd gaat in' }}
message: |
{{ 'De klok wordt vannacht een uur terug gezet' if currDST > nextDST else
'De klok wordt vannacht een uur vooruit gezet' }}
mode: single
All kudos how to determine DTS changes are for the authors above 
3 Likes
I never realized we could set those variable in the trigger block like that, and always worked around it by moving all to the action block
alias: DTS changes
description: Notify at 20h when DTS changes tonight
trigger:
- platform: time
at: "20:00:00"
condition: []
action:
- variables:
currDST: "{{ now().timetuple().tm_isdst }}"
nextDST: "{{ (now()+timedelta(days=1)).timetuple().tm_isdst }}"
winter: "{{currDST > nextDST}}"
- condition: >
{{ currDST != nextDST }}
- service: notify.notify
data:
title: >
{{ 'Winter'' if winter else 'Zomer'}}tijd gaat in
message: >
De klok wordt vannacht een uur {{'terug' if winter else 'vooruit '}} gezet
mode: single
looking for the documentation on that, to figure out if there are specifics to take into account…
;–)
nvm, it is hidden here Automation Trigger - Home Assistant…
so the shorter version:
- id: notificatie_dst_wissel
trigger:
platform: time
at:
- '10:00'
- '19:00'
variables:
curr: '{{now().timetuple().tm_isdst}}'
next: '{{(now()+timedelta(days=1)).timetuple().tm_isdst}}'
winter: '{{curr > next}}'
condition:
>
{{curr != next}}
action:
service: notify.notify
data:
title: >
{{'Winter' if winter else 'Zomer'}}tijd gaat in
message: >
De klok wordt vannacht een uur {{'terug' if winter else 'vooruit '}} gezet
I also found out recently that variables already can be defined in the triggers. The real power of that is that the variables can be set differently for various triggers 
That can save logic to evaluate trigger ids in the actions for particular automations and trigger based templates
yes, ive been looking for tha for some time, but just hadnt realized these were available already.
Doesnt stand out somehow in the docs…
now back to my yaml and find those automations…