A system needs to find and address different objects efficiently and accurately while remaining easy to understand, develop and keep up.
A business needs to track periods of time. This is a special case of the Range pattern, where the data values are date and time related.
A period can be constructed with a single boundary and an interval. As most actions with periods rely on testing its boundaries, this approach would need continuous calculation of the opposite boundary. Conversely, the interval can always be calculated from the two period boundaries and is used less often.
A business needs to bucket sets of consecutive, ordinal, data for aggregation purposes like age group, salary band, period, life cycle phase, and so on. This is different from grouping non-consecutive, nominal, data into buckets, such as hierarchies.