Hi Aziz,
You can use standard function to arrive at the logic. Something like below:
Make sure you use date format as yyyyMMdd for currentDate. For Input date(Begda) in my screenshot, you can use the date field from source (delivery date). this can be in any format but make sure you change the source field date format in standard Date functions, DateAfter or DateBefore.
It was not clear from your post on what you plan to populate if the above condition is met so I have left it here. You can build your logic on top of the logic above. 
Hope it helps!
Ambrish