Sometimes you might see a note on the dashboard or the API that indicates we have mixed-duration interval data for a particular meter. This means that not all of the intervals for that meter have the same length. UtilityAPI collects data from a variety of sources so this can happen when a utility provides different types of interval data in different places.
For example, we might collect 15-minute interval data from Green Button Download My Data and then collect hourly data from the utility's website to fill in gaps in the 15-minute data. This results in a situation where most of the intervals for that meter are 15-minute but there are certain periods that have hourly data because 15-minute data wasn't available.
Normally, our API and file exports (intervals_csv etc.) only include interval data that matches the primary duration for a given meter. For example, if a meter has mostly 15-minute interval data then we'll only show that data on the API and in the file exports. This simplifies things for users who need all intervals be the same length for their analyses (e.g. through Energy Toolbase).
To view all of the available interval data, regardless of duration, users can download the intervals_csv_mixed and intervals_xml_mixed file exports or include the allow_mixed=true option on the intervals API endpoint (https://utilityapi.com/docs/api/intervals/list#allow_mixed).