The 'Hour' dimension reports the hour that a given metric occurred (rounded down). The first dimension value is the first hour in the date range, and the last dimension value is the last hour in the date range. This dimension is valuable for trended reports, as it allows you to see metrics over time.
Populate this dimension with data
This dimension works out of the box for all implementations. If a report suite contains data, this dimension works.
Dimension values include a given hour within a report's date range alongside its date. It is formatted as HH:HH YYYY-MM-DD .