I frequently create Date groups in my Qlik apps to facilitate selections like “Yesterday” or “Last Week”. Some years ago I published a pattern for creating Date groups in the Recipes section of QlikCookbook.com and it’s been a very popular download. I’ve responded to a few requests on Qlik Community looking to do the same thing for Time groups, so I decided to publish a recipe for Time Grouping as well.
The recipe demonstrates selecting ranges such as “Day Shift”.
How do we create ranges that map to our data? In the script, create a Range table that defines range Names, Start and End times.
Range as Range,
Time#(RangeStart, 'hh:mm:ss') as RangeStart,
Time#(RangeEnd, 'hh:mm:ss') as RangeEnd
Range, RangeStart, RangeEnd
Midnight Shift, 00:00:00, 05:00:00
Early Morning, 05:00:01, 09:00:00
Daylight, 06:00:00, 17:59:59
Day Shift, 09:00:01, 17:00:00
Early Evening, 17:00:01, 20:00:00
Evening, 20:00:01, 23:59:59
12am-6am, 00:00:00, 05:59:59
6am-12pm, 06:00:00, 11:59:59
12pm-6pm, 12:00:00, 17:59:59
6pm-12am, 18:00:00, 23:59:59
Then use IntervalMatch to link the time field in our data (EventTime in this example) with the Range field.
JOIN (Ranges) IntervalMatch (EventTime) LOAD RangeStart, RangeEnd RESIDENT Ranges;
// No longer need RangeStart, RangeEnd, but may keep them for documentation or debugging.
DROP FIELDS RangeStart, RangeEnd;
There are additional notes provided in the downloadable example, but that’s it for the basic pattern. You can download the example from here Time Grouping
You may have noticed I used Time#() to read the text time values. That makes it easy to write the range values as readable hh:mm:ss.
If you are generating the ranges using another technique like Interval#() or division, be mindful of rounding. A Qlik time value is represented numerically by the fraction of 1, a whole day. 0.5 is 12:00:00 PM, halfway through the day.
There are four methods I’m aware of to generate a Qlik time. For example to generate the numeric time value corresponding to 12:00:05 AM:
All four will generate a floating point number to represent the time. Will they produce exactly the same result? Results that would pass an equality test?
Time#() = Interval#() = MakeTime() = x/y?
For some inputs they are equivalent. For a significant number of inputs the odd man out is Interval#(). Given the 86,400 second values in a day, Interval#() will not match the others 36% of the time. Try sharing that interesting fact with your spouse at the breakfast table.
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