formul help to calcaulte the aging with two column under criteria

hi excel experts

i looking for some result from two column

like A and B have dates column named A as SUBMIT AND B as RECEIVED

1. If No Date In Sumit And Date Is In Received Means Result Blank
2. If Date In Submit And No Date In Received Means Result Aging With Today Date
3. If Date In Submit And Received Also Result Aging Between Submit And Received
4. If Both Column Blank Result Blank
here formula before logica test,

for 2 result CLEAN(IF(TODAY()-AA7>=30,">30 Days",IF(TODAY()-AA7>20,"21-30 Days",IF(TODAY()-AA7>15,"16-20 Days",IF(TODAY()-AA7>10,"11-15 Days",IF(TODAY()-AA7>5,"6-10 Days",IF(TODAY()-AA7>3,"3-5 Days","0-2 Days")))))))

for 3 result CLEAN(IF(AA7-AB7>=30,">30 Days",IF(AA7-AB7>20,"21-30 Days",IF(AA7-AB7>15,"16-20 Days",IF(AA7-AB7>10,"11-15 Days",IF(AA7-AB7>5,"6-10 Days",IF(AA7-AB7>3,"3-5 Days","0-2 Days"))))))))


find the attachment... you understand than me....