Transform date to MM-YYYY

Thank you so much for the quick response. My date type is definately date. Can you confirm what I should be listing as 'table'? I am connecting to an excel file and the tab I am using is called 'Sheet1'. I have no other data files, connections, etc. 

If I enter the following formula, I recieve the error below. Is my syntax correcr? =FORMAT(Table[date], "YYYY-MM")

Expression.Error: The name 'FORMAT' wasn't recognized.  Make sure it's spelled correctly.

Pictures attached for both ways I have tried this. 

Thank you!!

Hi jleibowitz,

For my test, I create a calculated column using DAX formula in Power BI datamodel, while you create a custom column in Query Editor. DAX and Power Query are different computer language. Please clear them. If you want to create a custom column using Query statement, you should use the following formula.

=Number.ToText(Date.Year([Date]))&"-"&Number.ToText(Date.Month([Date]))

Best Regards,
Angelia