Date Format contains random numbers in Report Builder

[JayneBeetham]

I'm fairly new to Report Builder (though very familar with Power BI Desktop/query) and have fallen at the first hurdle!

I have a date field in my dataset but want to format it to appear as a long date (eg. Wednesday 10 September 2025) I am doing this using the 'Number > Format' section of the Properties pane using the following expression: 

=FormatDateTime(Table!Date_Field.Value,DateFormat.LongDate)

I have also tried: 

=Format(Table!Date_Field.Value,"dddd dd MMMM yyyy")

And in both instances it ouputs something like this: 

With random numbers in the field as opposed to being formated correctly

Does anyone have any idea how I can fix this?

[v-echaithra]

Hi @JayneBeetham ,

We’d like to follow up regarding the recent concern. Kindly confirm whether the issue has been resolved, or if further assistance is still required. We are available to support you and are committed to helping you reach a resolution.

Best Regards,
Chaithra E.

[v-echaithra]

Hi @JayneBeetham ,

May I ask if you have resolved this issue? Please let us know if you have any further issues, we are happy to help.

Thank you.

[v-echaithra]

Hi @JayneBeetham ,

I hope the information provided is helpful. I wanted to check whether you were able to resolve the issue with the provided solutions. Please let us know if you need any further assistance.

Thank you.

[v-echaithra · Accepted solution]

Hi @JayneBeetham ,

Check the Field Data Type in Report Builder:

Open the Dataset. In Report Builder, go to the Report Data pane (on the left side) and locate your dataset.

Inspect the Field's Data Type:

Right-click the dataset and select Dataset Properties.
Under the Fields section, find the field you're interested in.
Right-click on the field and choose Properties.
Check the Data Type:
In the Field Properties window, check the Data Type property. This will tell you whether the column is recognized as a date, string, integer, etc.

Hope this helps.
Chaithra E.

[v-echaithra]

Hi @JayneBeetham ,

In your dataset query, check whether the date field is being returned as a proper DateTime.If you're querying from SQL, run: SELECT DATA_TYPE FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'YourTable' AND COLUMN_NAME = 'Date_Field'
It should return datetime, date, or datetime2.
If you’re using Excel or CSV, Report Builder often treats everything as a string, so you need to explicitly convert it.

To debug, just temporarily place this in a textbox:
=Fields!Date_Field.Value
Then preview the report. If you see numbers like 1757519949510, that’s not a date — it's probably a timestamp, like a UNIX or .NET ticks value.
If It's a Timestamp, you need to convert it manually. For example, if the value is in UNIX epoch milliseconds, use:
=DateAdd("s", Fields!Date_Field.Value / 1000, #1970-01-01#)
Then wrap that in a Format():
=Format(DateAdd("s", Fields!Date_Field.Value / 1000, #1970-01-01#), "dddd dd MMMM yyyy")

If you want it to be only date rather than datetime, you can format it this way in power query editor.

Thank you.

[mh2587]

Wrap the field in CDate() to force it into a DateTime type before formatting:

=Format(CDate(Fields!Date_Field.Value), "dddd dd MMMM yyyy")

[JayneBeetham]

Unfortunately this hasn't resolved it: 

[v-echaithra]

Hi @JayneBeetham ,

Make sure that the Date_Field in your dataset query is a DateTime type. If your dataset is SQL-based, run the SQL query and ensure the field is returned as a true DateTime. If you're using a CSV or Excel file, double-check that the column isn’t being read as a string.

Wrap the field in CDate() as previously suggested, but using this syntax:

=Format(CDate(Fields!Date_Field.Value), "dddd dd MMMM yyyy")

if you're sure the field is already DateTime:

=Format(Fields!Date_Field.Value, "dddd dd MMMM yyyy")

Hope this helps.
Thank you.

[JayneBeetham]

Hello,

Thank you for your help. Apologies for late reply, I am onl able to work on this project a little each week as it's something I'm doing to upskill myself in between my regular work. 

I used your first option as I cannot be confident the field is formatted as a date in my dataset which produced this: 

I then tried your second solution and it gave the same.