Workflow to alert users when training is due

Hello,

Thank you all for your replies.

I am working in SharePoint 2013 with Ninetex workflows and am attaching a picture.

I would like a notification when the cell is empty and another email 21 days from due. all dates will be different in each cell.

The Name 1 and name 2 will be email addresses with the column name is EmpName

Thanks

Tim