createdat

CreatedAt, sometimes written as created_at, createdAt, or createdat, is a metadata field used in database records and software objects to store the timestamp of when the item was created. It serves auditing, sorting, and historical analysis.

Typically stored as a date-time value (DATETIME, TIMESTAMP) or as an ISO 8601 string, often in Coordinated Universal Time (UTC) to avoid time zone ambiguity. Some systems use a Unix epoch integer representing seconds or milliseconds since 1970-01-01.

Naming conventions vary by language and framework. Some codebases adopt created_at with underscores, others use createdAt in camelCase, and a few use createdat as a single word. In many frameworks, the field is automatically set on record creation (for example, Rails' ActiveRecord maintains created_at).

Common practices include making CreatedAt immutable after creation, indexing the field for efficient queries, and pairing it with UpdatedAt for change tracking. When displayed to users, the value may be formatted to local time or shown in relative terms (e.g., "2 days ago").

Related concepts include UpdatedAt, DeletedAt, and timestamps in general. The term is widely used across relational databases, NoSQL stores, and APIs, reflecting the need to record the origin time of entities.