The start date in Calendar function can not be later than the end date.

[VirajT]

Hi All,

I constantly get this above error message when my PowerBI Report is refreshed but unfortunately, I can't even spot the error in Desktop. 

The Data Source is from multiple locations, ADO, Sharepoint, OData and also has about 6-7 tables along with way too many measures and queries under each. 

Is there an easy way for PowerBI to take me directly to the place its showing this error for? Or let me know the name of the measure or M code line?

Thanks!

[v-hjannapu · Accepted solution]

Hi @VirajT,

Thank you  for reaching out to the Microsoft fabric community forum.
Thank you @lbendlin, and @danextian for reply regarding issue.

Blank or null dates in your data can mess up measures or queries. In Power Query, filter out nulls or use COALESCE to set a default date.

In Power BI Service, disable refresh for all tables, then re-enable them one at a time to find the failing one.

Double-check that your ADO, SharePoint, and OData credentials are valid in the Service, as they might have expired.Since you have multiple tables and queries, focus on any that rely on dynamic dates and ensure their source data is clean.
Hope the above provided information help you resolve the issue, if you have any further concerns or queries, please feel free to reach out to us.
Regards,
Harshitha.

[v-hjannapu]

Hi @VirajT,
I hope the information provided above assists you in resolving the issue. If you have any additional questions or concerns, please do not hesitate to contact us. We are here to support you and will be happy to help with any further assistance you may need.

Regards,
Harshitha.

[v-hjannapu]

Hi @VirajT,
I hope the above details help you fix the issue. If you still have any questions or need more help, feel free to reach out. We’re always here to support you.

Best Regards,
Harshitha.

[v-hjannapu]

Hi @VirajT  ,

I wanted to follow up and see if you have had a chance to review the information that was shared. If you have any additional questions or need further clarification, please don’t hesitate to reach out. I am here to assist with any concerns you might have.

Regards,
Harshitha.

[lbendlin]

Most likely your data contains blank dates too. Use COALESCE and MIN and MAX to cover all possible scenarios.  Spend time cleaning your source data.

Note:  Dates are usually immutable. There is no point creating a calendar table in Power Query or in DAX.  Use a precomputed external reference table.

[danextian]

There is no direct way. If you're CALENDAR formula references columns as the min start and end dates, ensure that they have the same date or the end date is always later than the max date. I normally do something like this:

CALENDAR ( MIN ( 'table'[start] ), MAX ( 'table'[end] ) )

The key is looking into the min and max values of the columns being referenced in your formula.

[VirajT]

I get what you are saying, but I have gone measure by measure to see which formula is failing and none of them do. 

Also this started today 15/07/2025. None of my formulas use this as a specific date!

Isn't there a way for PowerBI to recognize which table or which formula is giving me this error on refresh?