The Dates module in Julia provides a robust, hierarchical framework for managing temporal data through three primary immutable types: Time (clock-based), Date (calendar-based), and DateTime (combined).

1. Namespace Management

Choosing how to load the module dictates your interaction syntax:

• using Dates: Brings all exported functions into Main. You can call today() directly.
• import Dates: Functions must be explicitly prefixed (e.g., Dates.now()). This is safer for large-scale engineering to avoid name collisions.

2. Accessors & Extraction

Beyond creation, Julia allows surgical metadata extraction using specialized functions like year(), minute(), or dayofweekofmonth() to identify specific patterns (e.g., the third Friday).