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If you were to create a parameter where you could enter the date/time/hour, then you could identify anything where that time fell between the start and end times. So a calculated field like:
[Start Time] <= [Parameter Time] AND [End Time] >= [Parameter Time]
would identify the overlapping bars. For example, place that calculated field on color and all the bars overlapping the box above above would be easily identifiable.
If you wanted to further count the number of overlaps, you could use a table calculation to count them. It might look something like:
WINDOW_SUM(SUM(IF [Is Overlapping] THEN 1 ELSE 0 END))
(where [Is Overlapping] is the original calculated field)
Hope that gets you started. If you'd like, please post a packaged workbook and I'd be happy to take a look!
I am grateful for this thread, as I have been working on the same problem.
I used the Superstore Data and employed Mr. Milligan's helpful suggestions.
It did get me started, but I'm having difficulty creating the histogram of counts over time
(mock up desired histogram below).
concurrentHistogram.twbx 993.1 KB
This query appears to fall in line with the following thread:
I found Mr. Jackson's Method 2 to be useful in the attached example twbx.
Method 1 may be more helpful for the original poster's question.
concurrentHistogram2.twbx 1,002.5 KB
If you share a packaged workbook with dummy sample data, it will make it easier to help and communicate more precisely, and the answer(s) will also be much easier to understand for you and other learners reading along.
Ps. I have added this question to a collection of similar questions which deal with start and end dates:
The specified item was not found.