Datetime column appearing as time only in lakehouse

[need_a_name]

There is a possible bug in the lakehouse view where the datetime type columns are showing up as time only in the Lakehouse view.
Show below is an example. We find this in many other tables too.

The above table is created using a notebook and the lakehouse is with schema enabled (Preview). 

While this appear as a time, the underlying data seems to be properly saved. In the sql end point and in the dataset, it appears as datetime type itself.

 Regards

[burakkaragoz]

Hi @need_a_name ,

Yeah, this is a known quirk when working with datetime fields in Fabric notebooks and pushing them to Tableau. What’s happening is that Tableau sometimes misinterprets the datetime column as just a time field, especially if the data is inferred or cast in a way that loses the date portion during the transfer.

Here’s a couple of things you can try:

1. Explicitly cast the column in your notebook before writing to the table:

   df = df.withColumn("your_datetime_col", col("your_datetime_col").cast("timestamp"))

This helps ensure the schema is preserved correctly.

1. Check the data preview in Fabric before publishing. If it shows the full datetime there, then the issue is likely on Tableau’s parsing side.

2. In Tableau, try changing the data type manually in the data source tab. Sometimes it defaults to "Time" if the first few rows don’t include a full datetime.

If none of that works, yeah, raising a support ticket is a good idea. But I’d also recommend checking if the issue persists when using a different ingestion method (like exporting to CSV and uploading manually) just to isolate whether it’s a Fabric or Tableau-side issue.

If my response resolved your query, kindly mark it as the Accepted Solution to assist others. Additionally, I would be grateful for a 'Kudos' if you found my response helpful.

[suparnababu8]

Hi @need_a_name 

Yes you are correct. It's a bug. I replicated your scenario. When I created a table by using notebooks as hwon like below.

After writing this to Lakehouse as delta table. Datetime column is showing only time and Date column showing alos time. Pls see below pic.

Let's wait for CST team repsonds to this issue or You can raise a support ticket here Microsoft Fabric Support and Status | Microsoft Fabric 

Any way thank you for asking this question🙂

Did I answer your question? Mark my post as a solution!

Proud to be a Super User!

[need_a_name]

Thanks for taking time and looking at it. It seems the issue is fixed now. I can see the full datetime in the columns now.

[v-veshwara-msft · Accepted solution]

Hi @need_a_name ,

Thank you for confirming that the issue is resolved, and you’re now able to see the full datetime values in the Lakehouse view.

It seems like this was a temporary glitch that has now been resolved. We appreciate your engagement in the community and your patience while the issue was addressed.

Also thanks to @suparnababu8  for the prompt response and valuable contributions to the community.

Please feel free to reach out if you encounter any further issues or have any questions.

Please consider marking the helpful reply as Accepted Solution and giving kudos to assist others with similar issues.

Thank you.

[suparnababu8]

Yes, issue is fixed. Now am able to see the correct data

Thanks for letting me know!🙂

Did I answer your question? Mark my post as a solution!

Proud to be a Super User!