Elapsed Days

Hi I am new to power BI 

I have created a flow to update a power BI dataset and then created a report from it.

All has worked well. 

My time stamp is  shown as: 03/27/20 12:33:46 PM from the microsoft form.

I need to create a todays date to calculate the days elapsed since a responce was last recorded..

Looking at DATEDIFF etc it should be reasonabley easy, but i cant use power bi desktop to make a custom table as its greyed out.

Table on my report below which needs a third colume with the days elapsed

 Do i need to sperate the time as the mark as date table is all greyed out as well?

Is there a visual that already exsists for this task?

condtional formating maybe one to highlight x amount of days as bands but i cant in the current format.

Any help would be much appricated. 

Richard