What is the Umm al-Qura Calendar?

Umm al-Qura is distinct from a generic tabular Islamic calendar and from local observational determinations used elsewhere.

How the calendar is structured

Published Saudi month dates based on defined astronomical criteria and official tables.

Where and why it is used

Region: Saudi Arabia. Primary context: Saudi official and religious date presentation.

History and development

The system belongs to the Modern layer of the archive. Its origin is summarized as Modern official computational system. 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: Unicode CLDR / Saudi calendar references.