Queries :: Sum Between Two Times

I work for a chemical company, over the course of the day there are 2 shifts, one from 07:00 - 19:00 and the other from 19:00 - 07:00. I want to measure the amount of time a piece of equipment has been offline for, and Sum these times for each shift, these pieces of equipment can go offline multiple times per day which is why I need the sum function. The fields I currently have are:

[Date1] : The date at which it went offline
[Time] : The time at which the piece of equipment went offline
[Duration] : The length of time it was offline for

For each day I wish to sum the offline time in two fields called:

[Shift 1]: The previous nights shift (between 7pm the day before and 7am that day).
[Shift 2]: The days shift (between 7am and 7pm that day).

Where to begin but the logic should be something like:

[Shift 1] = Sum of [Duration] For(([Date1]-1 and [Time] between 19:00 and 23:59) And ([Date1] and Time between 00:00 and 07:00))

[Shift 2] = Sum of [Duration] For([Date1] and [Time] between 07:00 and 19:00)

I currently have two tables storing all this data, one containing [Date1], and another containing the breakdown information such as [Duration], [Time] etc. They are linked by the [Date1] relationship. The reason for the first table only having the [Date1] field is because it is a Main Form which contains various sub-forms.