To find the total number of Item, if only due date is present

[Anonymous]

Dear All, 

I am working on my first assignment in Power BI and your support would be highly appreciable in this regard. 

Background:

I have an excel file, which I have transferred in Power BI by using "Get Data-Web" option. In the Excel file, there is a column which is known as "Due Date". It means within this date, one need to complete the task.  Other than that, I dont have any Date values in the excel sheet. 

Question: 

- I would like to calculate the total number of open items, in case the task has been completed within this due date How can I do it ? 

I tried using the following DAX function : 

CALCULATE(COUNTROWS('File Name'),FILTER('File Name'

After this I am really clueless, what should I do. Kindly help me with the same. 

Thanks 

Shaurya