Fill missing hours automatically excel

Ok, here's one way

24 hrs * 60 mins * 60 seconds
24 * 60 * 60 = 86,400 seconds

Time in Excel is held as an internal decimal number, a fraction of 1.00
So 1 = a full day, 0.5 = 12noon
More importantly 8:00am would be 0.3333 RECURRING. This may affect any MATCHes so you need to MATCH "hh:mm:ss" against "hh:mm:ss" for accuracy.


1) Insert a column before column A

2) in A1
=TEXT(B1,"hh:mm:ss")
copy this down as far as the number of rows you have, in your example 10624

3) in D1
=TEXT((ROW()-1)/86400,"hh:mm:ss")
and copy down as far as row 86399

4) in E1
=IF(ISNA(MATCH(D1,A$1:A$10624,0)),0,INDEX(C$1:C$10624,MATCH(D1,A$1:A$10624,0)))
and copy down as far as row 86399