Average hourly data

Dear PurpleAir Support,

One question on the averaged hourly data. Is the time the start time of average or the end time of average? For example, for a data record with time stamp 2020-09-29 02:00:00, is the average over 01:00:01 to 02:00:00 or average over 02:00:00 to 02:59:59?

Thank you!