Water Log get moved to previous date

[EntropicMaximum]

I originally posted this in the Third‑Party Integrations forum — sorry for the cross‑post. Since it directly affects the API, I believe it’s also relevant here.

When modifying water logs, the API shifts the date backward by one day.

Here’s the link to the original post with the full request/response details. https://community.fitbit.com/t5/Third-Party-Integrations/Water-Log-get-moved-to-previous-date/m-p/58... 

[EntropicMaximum]

Can someone check if they’re having this issue as well?

I'm already talking to support, but they keep sending me through the standard checklist — clear cache, restart the phone, etc. I even had to send them a video of how I log water in the app.

I'm 99% sure this is an API problem, so there’s nothing I can fix myself.

Honestly, it’s getting pretty frustrating.

I was under the impression that this is the official API support forum. If that’s not the case, could someone point me to the correct place for API‑related issues?

[DorisFitbit]

Hi @EntropicMaximum 

Welcome to the community!

We will check and back to you shortly. Please feel free to let us know if you have any additional questions. 

[EntropicMaximum]

Hi @DorisFitbit

Are there any news on this issue?

[DorisFitbit]

Hi @EntropicMaximum 

Thanks for following up. 

Upon review, we were unable to reproduce the issue in our end. However, given that your logs show the activity occurred at 23:27 CET, we suspect the proximity to midnight may be a contributing factor. To help us narrow this down, we recommend the following:

• Daytime Testing: Please try to reproduce these steps during the day, further away from the midnight threshold. This will help us determine if the issue is specifically tied to how the system handles date transitions in your local timezone.

• New Google Health API: We also suggest testing this workflow using the new Google Health API. As we transition to this next phase of the Fitbit Web API, you may find that this updated infrastructure handles these logs more consistently. You can find the technical details here: Introducing the next phase of the Fitbit Web API.

Please let us know if the date shift persists during your daytime tests or when using the new API. We’re happy to take a deeper look once we have those results.

[EntropicMaximum]

@DorisFitbit The issue appears to be timezone dependent.

I performed additional test cases a few minutes ago (13:20 local time in germany):

When my account timezone is set to Europe/Berlin, updating a water log consistently moves the entry to the previous date.

When switching the account timezone to America/Los_Angeles, the issue disappears immediately.

This suggests that during UPDATE there is an issue with timezone handling, which results in an unintended day shift.

[DorisFitbit]

Hi @EntropicMaximum 

Thanks for the updates. To ensure we can replicate your environment exactly, could you please provide the following details regarding your Europe/Berlin timezone testing?

• Fitbit Profile Timezone: Is the 'Set Automatically' toggle enabled in the Fitbit app settings? (If disabled, please confirm the manual setting).

• Google Account Timezone: What is the primary timezone currently set for your Google Account?

• Additional Context: Please share any other device-specific settings or hardware info that might be relevant.

Once we have these configuration details, we’ll work to reproduce your specific environment for further testing and analysis.

[EntropicMaximum]

Hi @DorisFitbit,

sorry for my late reply.

In my fitbit profile my timezone is set to automatic. The timezone shows as Europe/Berlin

My Google account timezone should be GMT+2 (Central European Summer Time). In the web interface of my Google Account I couldn't finde any settings. Only in the Google Galendar App. So I assume it's GMT+2. Where exactly can I finde this information. I don't use GMail, by the way.

My phone is also set to GMT+2 with automatic settings. And I don't have any special configurations enabled.

I don't know if it's a problem with this thread, but my previous answers keeps disappearing. Maybe a short outage.

Kind regards