Help with creating uptime/downtime calculation/analysis

Hello all,

I am a low-intermediate user of excel and am in need of advice. I have a machine that keeps daily logs of its activity and outputs the date/time every time it runs a load. The load time is fairly short, being from 10-50 seconds long. This means I have a log file that has hundreds of rows of different times (each day).The time format is also in m/d/yyyy h:mm:ss.
What I would like to do is take all of the times in the Time column (below) and calculate uptime/downtime.
When trying to create formulas witht this formatting, I am getting strange numbers. Here is a sample of the data I am using from the log file (I have also attached the actual log file)data.xlsx:

Time JobName Energy CompelitionStatus
2/11/2013 14:22:22 13187 65 1
2/11/2013 14:22:33 13187 65 0
2/11/2013 14:26:17 13275 65 1
2/11/2013 14:27:10 13275 65 1
2/11/2013 14:29:45 13275 65 1
2/11/2013 14:30:18 13275 65 1
2/11/2013 14:30:27 13275 65 1

You can see that between each time recording there is "downtime". I would like to capture this downtime, total it, and track it. In turn I would also like to capture the uptime as well. There are also durations of lunch breaks and such that account for a larger volume of time that would be captured as well.


Thank you for any help you can provide on this matter.