What is the World Calendar?

The World Calendar proposal aimed to make quarters structurally identical. Objections included the treatment of extra days outside the seven-day week cycle.

How the calendar is structured

Quarter-based perpetual calendar with extra year-end and leap days.

Where and why it is used

Region: International proposal. Primary context: Calendar reform history.

History and development

The system belongs to the Modern Proposed layer of the archive. Its origin is summarized as 20th century calendar reform. CalculatorWiser separates historical reconstruction, religious observance, civil use, and modern technical standards so different systems are not treated as though they all work the same way.

Visual reference gallery

Conversion and accuracy notes

Some calendar systems can be converted deterministically with modern algorithms. Others depend on observation, local authority, historical reconstruction, or regional practice. CalculatorWiser marks those distinctions rather than presenting uncertain dates as exact.

Research trail

This entry is part of the research-backed World Calendar Archive. Primary research anchor for this entry: Calendar reform references.