RFC 3339 is a standard that defines a format for representing date and time in a way that is both human-readable and machine-readable. It is widely used in internet protocols and applications to ensure consistency in date and time representation. The format includes the date, time, and time zone, allowing for clear communication of temporal information across different systems. The standard specifies a format like "YYYY-MM-DDTHH:MM:SSZ" where "T" separates the date and time, and "Z" indicates Coordinated Universal Time (UTC). This structured approach helps avoid confusion caused by different date and time formats used around the world.