Fill In Missing Sequential & Repeating Numbers

I am busy with a very large dataset +-20 000 records showing the movement data
and I am having problem with inserting missing data: I have columns titled day hour and position, but multiple records for each as data was initally recorded by second. Data looks like this

Day Hour Position
1 2 Z5
1 2 Z5
1 3 Z5
1 3 Z4
1 16 Z1
12 2 Z3
13 0 Z3

What I need to end up with is a sequential dataset running from day 1 to 388 with hours 1-24 of each day. Positions need to be filled in for all data recorded (see above). The big problem is that movements between positions need to be recorded and accounted for i.e if more than >80 of time was spent at the position Z3 then that is the position for the hour.