Excel: Count Total Schedules at 30 Minute intervals taking day into account - excel

Question

In assessing how many agents can be added to certain times of day without exceeding the number of seats in the call center, I'm trying to discern how many agents are scheduled for each half hour interval on each day of the week.
Using the =SUMPRODUCT(((A$2:A$1000<=D2)+(B$2:B$1000>D2)+(A$2:A$1000>B$2:B$1000)=2)+0) formula I've been able to identify how many total agents work for each interval, however this doesn't take the day of week into account.
I currently have my spreadsheet setup this way:
K is the start time of the shift, L is the end time of the shift, M to S pulls data from another sheet that shows a 1 if the agent works on that day of the week and 0 if they do not, and then U has all the time intervals listed out. In the example, it's cut off but the columns continue down as needed. U goes to 49 and I've just been using a range from 2 to 500 for the others as we currently do not have that many shifts and I'm leaving space for the moment.
After some Googling, I tried =SUMPRODUCT(--(M2:M500="1"),(((K$2:K$1000<=U2)+(L$2:L$1000>U2)+(K$2:K$1000>L$2:L$1000)=2)+0)) but it only returns #VALUE! so I'm not sure what I'm doing wrong.
Any suggestions of how I can make this work? Please let me know if more information would be useful. Thanks.

Answer 1

=sumproduct(($K$2:$K$1000<=U2)*($L$2:$L$1000>=U2))
That will count the number of occurrences where the start time is less than or equal to the time in U2 AND the end time is greater than or equal to U2. It will check time from row 2 to row 1000. Any time one condition is checked and its true the comparison will result in value of TRUE and FALSE when its not true. The * act like an AND condition while at the same time converts TRUE and FALSE values to 1 and 0. So both conditions have to be true for a value of 1 to result. Sumproduct then totals up all the 1 and 0 to get you a count.
In order to consider the days of the week, you will need one thing to be true. Your headers in M1:S1 will need to be unique (which I believe they are). You will need to either repeat them in adjacent columns to M or in say V1 you have a cell that can change to the header of the day of the week you are interested in. I would assume the former so you can see each day at the same time.
In order to do this you want to add more conditions and pay attention to you reference locks $.
In V2 you could use the following formula and copy down and to the right as needed:
=sumproduct(($K$2:$K$1000<=$U2)*($L$2:$L$1000>=$U2)*(M$2:M$1000))
UPDATE #1
ISSUE 1 Time ranges ending the following day (after midnight)
It is based on the assumption that the ending time is later than the start time. When a shift starts at 22:00 and end at 6:30 as an example, our mind says that the 0630 is later than 22:00 because it is the following day. Excel however has no clue that 0630 is the following day and without extra information assumes it to be the same day. In excel date is stored as an integer and time is stored as a decimal. When you only supply the time during entry it uses 0 for the date.
In excel the date is the number of days since 1900/01/00. So one way to deal with your time out is to add a day to it. This way excel will know your out time is after your in time when the hour is actually earlier in the day.
See your sample data below.
Using your sample data, I did a straight copy of the value in L and placed it in M (=L3 and copy down). I then changed the cell display format from time to general. This allows you to see how excel sees the time. Note how all the time is less than 1.
In column N I added 1 to the value when the out time was less than the in time to indicate that it was the following day and we had not actually invented time travel. I also used the trick of a math operation will convert a TRUE/FALSE result to 1 or 0 to shorten the equation. I used =M3+(L3<K3) and copied down. You will notice in the green bands that the values are now greater than 1.
In the next column I just copied the values from N over using =N3 copied down, and then I applied just a time display format for the cell. Because it is only time format, the date is ignored and visually your time in column O looks the same as column L. The big difference is excel now knows that it is the following day.
you can quickly fix your out times by using the following formula in a blank column and then copying the results and pasting them back over the source column using paste special values.
=M2+(L2<K2)
The next part is for your time check. When looking at the 12:00 time you need to look at 1200 of the current day incase a shift started at 12:00 and you need to look at the 1200 period of the following day. In order to do that we need to modify the the original formula as follows:
=sumproduct(($K$2:$K$1000<=$U2)*($L$2:$L$1000>=$U2)*(M$2:M$1000)+($K$2:$K$1000<=$U2+1)*($L$2:$L$1000>=$U2+1)*(M$2:M$1000))
Note that the + in the middle of (M$2:M$1000) + ($K$2:$K$1000<=$U2+1)? This + acts like an OR function.
Issue 2 Time In/Out 15 minute increments, range 30 minute increments
You may be able to achieve this with the ROUNDDOWN Function or MROUND. I would combine this with the TIME function. Basically you want to have any quarter hour start time be treated as 15 minutes sooner.
=ROUNDDOWN(E3/TIME(0,30,0),0)*TIME(0,30,0)
Where E3 is your time to be converted
So your formula may wind up looking something like:
=sumproduct((ROUNDDOWN($K$2:$K$1000/TIME(0,30,0),0)*TIME(0,30,0)<=$U2)*($L$2:$L$1000>=$U2)*(M$2:M$1000)+((ROUNDDOWN($K$2:$K$1000/TIME(0,30,0),0)*TIME(0,30,0)<=$U2+1)*($L$2:$L$1000>=$U2+1)*(M$2:M$1000))
similar option could be used for the leaving time and rounding it up to the next 30 minute interval. In which case just use the ROUNDUP function. Though I am not sure it is required.