How do I change my query to display time-based results as HH:MM:SS?
You can change the time-based results of your queries in Explore by clicking on the chart configuration () menu. Click Display format and change the dropdown to Duration.
Changing the display format to Duration only works if your time-based metric is displayed in seconds. The duration display format is intended to convert metrics that are based on seconds to the HH:MM:SS format. It will not work for any other unit of time, such as minutes or hours.
For more information, see the article: Changing the format of results.