A particular period of time used for comparative purposes when measuring economic data.

  The period of time for which data used as the base of an index number, or other ratio, have been collected. This period is frequently one of a year but it may be as short as one day or as long as th [..]

A point in time used as a reference point for comparison with some later period.

Definition A specific time period used as a benchmark in measuring financial or economic data.

The period from which the weights for a measurement series are derived. The national income and product accounts (NIPAs)

The period between the morning and evening peak periods when transit service is generally scheduled on a constant interval. Also known as "off-peak period". The time of day during which vehicle requirements and schedules are not influenced by peak-period passenger volume demands (e.g., between morning [..]

As it relates to unemployment compensation, it generally consists of either 52 weeks or four of the last five quarters, immediately preceding the claimants benefit year.

See Off-peak Period.

The primary base period is the first four of the last five completed calendar quarters prior to the calendar quarter in which your claim is effective.

The period that provides the weights for an index is described as the base period.

A particular period of time used for comparative purposes when measuring economic data.