Time duration metric in HH:MM:SS format is correct for a single day, but when applied to the entire month, it is incorrect.

Available Time, defined as: The length of time that the Agent spent in the available state, is in seconds. I've converted the metric to HH:MM:SS format using the following calculation:

1. Calculation of: SUM([Available Time Seconds])/86400
2. Format Measure as ‘HH:MM:SS’ 

This produces the correct time available for a single day, however, when I filter for the entire month, we lose half the reported hours. Not sure how to address the issue.

Available Time for 8/7 is Correct

Available Time for 8/1-8/15 is Incorrect