New Excel User

Hi am a newbie excel and would like to know more about it since i am using it in my work. an i know this group will be a great help.

i have a question on how can i do averaging with multiple conditions. Release dates have blank dates and i don't want to include them. wondering what what's the best formula for this. appreciate your big help for this

Release Date PIC Days Aging
11/29/2016 HCCOMING 9
11/29/2016 ZMPEPITO 5
11/29/2016 ADMOLINA 6
ADMOLINA 8
11/30/2016 ROBALOSA 2
ZMPEPITO 6
12/2/2016 ZMPEPITO 28
12/3/2016 ROBALOSA 14
12/4/2016 ROBALOSA 20
11/29/2016 HCCOMING 13
HCCOMING 9