Evaluate if a date/time falls between Start Date & End D

[Don Click]

My application is to outages of an application in 15 minute intervals. When an outage occurs, we record the Start time and when it's resolved, that's the End Time. I need to look at each outage and determine which 15 minute interval it fell within. At the end of the day, I'll total the number of 15 minute intervals that have at least 1 entry where the Start End Time overlapped. I then can count how many 15 minute windows had an outage times 15 minutes and that will give the number number of minutes of outages for that given day/week. There can be multiple outages occuring at the same time, so I don't want to double count, I only need to know that there was an outage in that 15 minute window.

I have 2 columns, one for Start Date/Time (1/30/2006 7:00:00 AM) and one for End Date/Time (1/30/2006 7:20:00 AM). I'm allowing for 100 different entries of start/end times that may range from 10 minutes to several hours. I have another column (I'll call Window) that has the same format of dates/times from 1/30/2006 7:00:00 AM through 1/30/2006 18:00:00 PM in 15 minute intervals. I need to evalute if there is an entry in the Start and End times that falls within each 15 minute interval. In this example, the Start time of 7:00 and End Time of 7:20 will fall inside the 7:00 window and the 7:15 window. The purpose is to count how many Windows fall within a Start/End time.

I've tried a number of examples found on the website, SUMPRODUCT being one of them, but none returned what I expected. For example, I had 2 identical entries 7:00 to 7:10, but it only counted 1 of them.

Thanks for the help....

 

[Don Click]

I finally got it to work using =SUMPRODUCT((X10>=$D$35:$D$135)*(X10<$E$35:$E$135)) (as an example). It took a while to understand how SUMPRODUCT worked when using "--" and "*". The link below is a great website explaining how SUMPRODUCT actuall works.

http://www.xldynamic.com/source/xld.SUMPRODUCT.html#explain