weekbasedyear
A week-based year is the year used by the ISO week date system to label weeks. In this system, each date is assigned a week number and a week-based year. Weeks begin on Monday, and week 1 is defined as the week that contains the year's first Thursday (equivalently the week that contains January 4). The week-based year is designed so that weeks are grouped consistently across year boundaries, which means some days at the end of December may belong to the final week of the current year while others at the beginning of January belong to the first week of the next year.
The concept is standardized in ISO 8601 and is widely used for international business, scheduling, payroll,
A year in the ISO system can have 52 or 53 weeks. A 53-week ISO year occurs
In practice, the week-based year offers a stable framework for week-centered planning and reporting, independent of