DateId

DateId is a term used in information systems to denote an identifier associated with a specific date. It refers to a compact encoding of a date into a single value or to a surrogate key designed for date-related data modeling. In data warehousing and database design, DateId often serves as a date dimension key that enables consistent joins with fact tables and supports time-based analytics.

Common implementations encode year, month, and day into a numeric or string form. Examples include integers in the form yyyymmdd or fixed-length strings that can be sorted lexicographically. Some designs allocate a stable, monotonically increasing key per date, which remains constant regardless of the time of day or time zone. The choice of format affects readability, storage, and performance of queries.

Key properties of a well-designed DateId include determinism, monotonicity where appropriate, and timezone independence. DateId should be easily comparable and efficiently indexable, supporting fast range and grouping queries by date. It is typically convertible to and from standard date types and may be used across systems with differing locale settings.

Common use cases include data warehousing and business intelligence, where DateId serves as a stable surrogate key in a date dimension, ETL pipelines that normalize dates, and APIs or logging systems that require compact, sortable date references. Care must be taken to handle leap years, time zones, and future migrations that affect how dates are represented or parsed.

See also: Date dimension, surrogate key, YYYYMMDD encoding.