Sync SwitchBot Meter Pro (CO2 Monitor)'s time via Bluetooth

[FloEdelmann]

Integration name

SwitchBot Bluetooth

Link to integration documentation on our website

https://www.home-assistant.io/integrations/switchbot/

Describe the enhancement

The SwitchBot Meter Pro (CO2 Monitor) is already supported via the SwitchBot Bluetooth integration, i.e. temperature, humidity and CO2 level (as well as battery level and Bluetooth signal strength) are available as sensors in Home Assistant.

I suggest to automatically update the time and date visible on the device itself periodically with Home Assistant's time.

Use cases

The time displayed on the device gradually drifts away from the real time, and when daylight saving time begins/ends, it is suddenly an hour off. When connected via Bluetooth to the SwitchBot app on my phone, the time syncs and is correct again (for a few weeks).

However, I deleted the app after the initial install, because I don't want or need it on my phone. And even if I still had it installed, I had to manually open it and enable Bluetooth and connect to the SwitchBot Meter Pro (CO2 Monitor). This is cumbersome, and an automatic sync via the already established Bluetooth connection to Home Assistant would be much more convenient.

Anything else?

No response

[github-actions[bot]]

🏷️ I've automatically added the integration: switchbot label to help categorize this feature request.

[herpaderpaldent]

Subscribing to the threat as well, because i suffer from this timedrift as well.

[harry421hol]

Hi, have the same issue with one difference I've never installed the switchbot app, just used the Home Assistant integration.

[uwe678]

I have the same problem and am interested in the described solution.

[thany]

I bought mine today, and it automagically set the correct time... plus one hour 😀

So I thought it was on the wrong timezone or something, but I guess that's not a thing then. Pure coincidence.

[c0ldtech]

Same here. Wrong time zone and two minutes fast. Can't be coincidence though.
And I never used the app, so some kind of time sync must have happened either by HA or the Bluetooth bridge if that's possible.

[andreaskoelsch]

I guess it's just factory set? Would also have loved to not use the app, but installed it for FW update and time sync. Now, I only use it in HA

[thany]

@andreaskoelsch But that's not sustainable, as you'd need to sync time at least twice a year, when going in and out of DST. And possibly more often, since people (elsewhere too) seem to suggest its internal clock is inaccurate and can drift.

[andreaskoelsch]

You're right. That's why I subscribed to this issue, too 🙂

[elgris]

Hi folks!
Just a heads-up: I also decided to poke around the problem a bit (work in progress is in this branch), because I also got annoyed by the time drift of the Meter Pro :D. We need this change in the dependency lib to land first. And while we're waiting, just wanted to get some early feedback and guidance, because I'm not very familiar with this codebase.
My approach is to:

• make HA poll the current time from the Meter Pro and sync it when it drifts away too much. The poll interval is 1 minute. Maybe we could as well just sync time every minute?

• allow the user to force-sync the time with a button on the device card, just in case.

• (BONUS) allow setting the display time format (24h or 12h AM/PM).

So, what do you think? Would that work or can we make it better?

[thany]

Looks good. Let's make it happen 😎

Automatic time sync should be enabled by default though. It is in the nature of a bluetooth device to be connected to only one host at a time (no pun intended) and so HA will be the only available host to push the correct time.

[elgris]

Thanks! I just wanted to play it safe and start with off-by-default and make it on-by-default in the next release. But maybe I'm too cautious, let's change it :)

[mbinks]

Congratulations on the merge @elgris !

Sounds like it'll require a simple automation to set the time to the current server time, so as to avoid Mysterious Stuff Happening for No Reason. I'm excited to have the date display on the device be correct!

[c0ldtech]

Thanks for putting in the effort! For me personally it would be perfectly finde to just set the date/time at certain intervals. Assuming the internal clock is not horrible, even synching once a day should be fine. Maybe make it a user choice to specify how many hours there should be between each sync?

[c0ldtech]

I also think once a day is enough. I wouldn't try to make the logic overly complicated though. Maybe allow the time when the sync should happen to be adjustable. Or allow the sync to happen through cron syntax, that way this would be customizeable.
For example, I would just set it to sync every 6 hours or something, I'm not running on batteries. Even if I would, I'm not sure if that would significantly affect battery life even to have it run hourly, since communication happens way more often than hourly anyways.

[herpaderpaldent]

@elgris since you are only setting the unix timestamp in UTC https://github.com/sblibs/pySwitchbot/pull/433/files#diff-e0e7d3627a9f87a80fc7f30a2905799d930f39ea3d82b3ad88865f7287badd4bR100 you don't need to worry about seasonal time change.

I assume this is internally within switchbot solved with the date.

[FloEdelmann]

@herpaderpaldent I don't think that is the case; otherwise my device would have adjusted to DST / non-DST automatically even without sync, which it hasn't (see my initial post).

[mbinks]

What I'm concerned about with daily syncs is seasonal time change (winter/summer time). I don't know if the device handles it by itself, waiting for up to 24hrs to get it in sync would be weird.

Seasonal time changes happen at 2 AM local time ("falling" back to 1AM or "springing forward" to 3AM); if the sync happened at 3 AM you could do the daily sync and accomodate these changes.

[elgris]

Thanks all for the discussion! Syncing time daily at 03:00am sounds good to me. Opened home-assistant/core#161808, feel free to share feedback there.

[FloEdelmann]

As a summary for everyone following this thread:

A pull request has just been merged that adds a "Sync time" button entity to the integration:

• Control datetime on SwitchBot Meter Pro CO2 core#161808

This can be used in an automation, see the documentation pull request:

• Document syncing datetime on Meter Pro CO2 Monitor. home-assistant.io#43616

And for reference, the 12h/24h display time format can now also be changed via a select entity:

• Control time display format on SwitchBot Meter Pro CO2 core#163008

All of this should probably be released in 2026.3 🥳
Thanks @elgris!

[herpaderpaldent]

So DST change happend ... switchbot did not adapt ...

i somehow miss the following option

allow the user to force-sync the time with a button on the device card, just in case.

That does not exist for me.

[elgris]

@herpaderpaldent: Which version of HA are you running? Mine is 2026.3.1 and the force-sync button seems to be there: start from the Devices & Services / Integrations page, then go to the device, then check the button in the Configuration section of the device page.

We ruled out the automation magic during this discussion. As a user, you should be in control and you should configure automatic syncs yourself (here's the how-to, expand the "Syncing the device date and time with Home Assistant automatically" section).

[herpaderpaldent]

Hey @elgris

I am running 2026.3.4 - i was unprecise in my statement. The force-sync is available however the 3am sync that's what i was lacking of.

However. even after force-syncing yesterday my Meter: still no DST change. It's lacking an hrs behind.

[elgris]

Hm... let's debug it:

1. What system date/time does your HA instance show? I don't know if it's possible to check it in the Settings, so let's go the dev way :). Go to Settings -> Developer tools -> Template tab. There you can try adding {{ now() }} snippet to the template editor, then check how it renders on the right side. It will look something like this.
2. What activity logs does it show when you press that Force-sync button? (something like this).
3. Anything suspicious in the debug logs? (how-to enable and collect them: https://www.home-assistant.io/docs/configuration/troubleshooting/#debug-logs-and-diagnostics)

[herpaderpaldent]

Sure that is why i did not start my phone app

1. Time is correct

2. it shows correctly

3. Not that i can see anything .... issues is an empty array
   but the graph looks weird:

I just noticed an error message in the console. But not in the debug/logs

Uncaught (in promise)
Object { code: "unknown_error", message: "None (B0:E9:FE:56:F2:D2) - B0:E9:FE:13:37:D2: Failed to connect after 10 attempt(s): Timeout waiting for connect response while connecting to B0:E9:FE:13:37:D2 after 20.0s, disconnect timed out: False, after 20.0s" }
connection-mixin.ts:169:13

that MAC is actually my meter ....