I'm able to create the following calculated field in the Search app.
.... | eval KCQueueDuration = (strptime(KCQStartDate." ".KCQStartTime, "%Y-%m-%d %H:%M:%S")) - (strptime(KCQEndDate." ".KCQEndTime, "%Y-%m-%d %H:%M:%S"))
However, I'm not able to get it to work when I create this field using the Splunk Web App (Settings->Fields->Calculated Fields) or editing the props.conf file. The field doesn't show up in the list of interesting fields, when I just search for all events for the source type. If I use this process to create a calculated field that just contains 1 of the strptime functions, it appears in the list of interesting fields.
Below is an example of the event data.
KCUID=905252z911311o,KCQStartDate=2016-01-06,KCQStartTime=15:19:46,KCQEndDate=2016-01-06,KCQEndTime=15:19:48
I couldn't find anything indicating that this expression is invalid in props.conf. Is this a known limitation of calculated fields in props.conf?
I just tried this and it worked for me
EVAL-KCQueueDuration = (strptime(KCQStartDate." ".KCQStartTime, "%Y-%m-%d %H:%M:%S") - strptime(KCQEndDate." ".KCQEndTime, "%Y-%m-%d %H:%M:%S"))
I just tried this and it worked for me
EVAL-KCQueueDuration = (strptime(KCQStartDate." ".KCQStartTime, "%Y-%m-%d %H:%M:%S") - strptime(KCQEndDate." ".KCQEndTime, "%Y-%m-%d %H:%M:%S"))
I tried your expression, and it also worked for me. It was one of the expression permutations I didn't think of trying.
Thanks for your help resolving this issue.
Perhaps it is a permissions problem? In which app did you create the calculated field and what are its permissions?
Most likely its an ordering-of-the-knowledge-objects issue. Are any of the fields in your calculated field coming from an alias or lookup?
The fields in the calculated field expression are not alias or lookup fields. If I create a calculated field that just contains: strptime(KCQStartDate." ".KCQStartTime, "%Y-%m-%d %H:%M:%S"), it works. Likewise, it works if I create a calculated field with just strptime(KCQEndDate." ".KCQEndTime, "%Y-%m-%d %H:%M:%S"), it works.
The calculated field doesn't work when I tried to combine the 2 expressions to calculate a duration value.