SharePoint date field shows different dates to different users

[BillYoung-arm]

We've created thousands of records over the last year, with no similar problems.

The user enters a record via a Canvas app. The App mostly displays the correct entered dates for them and sends a confirmatory email with the correct dates showing (i.e. on reading the record, the email correctly gives the correct date, as entered). 
When viewed centrally, however, the dates generally show as the previous day and indeed act as that day

Even more oddly, I viewed the Power Automate that ran a "Get Items" against one of these records at 8:10 (BST) this morning, which showed the date as 28th July
    "ItemInternalId": "85809",

    "ID": 85809,

    "date": "2021-07-28"

…but when I ran the same process against the same record at 2pm, it shows as the 29th:

        "ItemInternalId": "85809",

        "ID": 85809,

        "date": "2021-07-29"

…thus even within my own observation, the date appears to have changed!

They have the same ID, so are clearly the same record and it hasn't been amended

The user is in France on CEST

I and the account that runs the flow are based on BST, so only 1 hour difference, thus a timezone issue seems unlikely, particularly during the middle of the day

The user was using Firefox on Linux and then tried Chrome on Ubuntu. Both seemed to produce mixed results in displaying the selected date

The tenancy is in EMEA

Does anyone have any suggestions for further investigation or causes?
Thanks

[v-bofeng-msft]

Hi @BillYoung-arm :

This is caused by the Regional Settings of the SharePoint site.

The date/time values in all lists in the SharePoint site default to local time. If the time zone set by your SharePoint site is UTC+1, then the time saved in your List is the time with a date offset (+1h). The reason for the problem you mentioned is because flow obtains the converted UTC time (reduced by 1h).

Best Regards,

Bof

[BillYoung-arm]

Thanks for the reply v-bofeng-msft

Site is UTC(Dublin, Edinburgh....) though, so we're plus one hour difference (BST) and our user is +2 hour diff (CEST)
If creating record in the first or last couple of hours of the day, I could understand but it was created at 8:10 (firmly into 29th July, but logged as 28th) and then seemingly changed by 14:00, so I don't think this would happen.

If you think so, please let me know  
Cheers

[v-bofeng-msft]

Hi @BillYoung-arm :

This may be due to daylight saving time.

I think this link will help you a lot:

Problem with UTC and daylight savings time? 

In addition,If the problem can not be resolved, you could consider creating a support ticket.

Best Regards,

Bof

[Powerplatform01]

@BillYoung-arm 

Take reference from this video. also request you to please subscribe this channel

https://youtu.be/NLEMPn-T3ns

[BillYoung-arm]

Hi Powerplatform01
Thanks for the reply.

I'm not seeing how this helps as the video refers to dates in Excel, stored as a number but AFAIK, this isn't how a SharePoint date field works.
If I run an int against the date, I get:
The template language function 'int' was invoked with a parameter that is not valid. The value cannot be converted to the target type.'

Am I missing something?

[Powerplatform01]

@BillYoung-arm 

Ok Bill No worries give me some time I will check again and let you know

Meanwhile please subscribe this channel.It motivates me to help you further

https://youtu.be/NLEMPn-T3ns

[BillYoung-arm]

Thanks again, have subscribed. It was a good video also 🙂