The 'Day' dimension reports the day that a given metric occurred. The first dimension value is the first day in the date range, and the last dimension value is the last day in the date range. This dimension is vital 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 the date of a given day. It includes the month, day, and year as part of the dimension value.