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Fasting Index

Ramadan fasting rules

A reference for what does and does not invalidate a fast during Ramadan, sourced to named scholars and shown school by school rather than flattened into one answer.

What this section does not do

This section does not issue religious rulings. Questions of what breaks a fast in Islamic law belong to a qualified scholar, and where a question is one of jurisprudence rather than physiology we say so and point elsewhere.

Why it is handled separately

The rest of this site answers a metabolic question using clinical evidence. Ramadan asks a different question, answered by a different discipline. Mixing the two would produce confident answers with nothing behind them, so the sections are kept apart with separate sourcing standards and separate reviewers.
The Ramadan day drawn as a 24-hour dial. The hatched arc runs from dawn to sunset and is the fast; the open arc is the window in which eating and drinking happen. Drawn here for a 13.5-hour fast. The real length depends on latitude and date.
The Ramadan day. The hatched arc is the fast, dawn to sunset; the open arc is the window in which eating and drinking happen. Drawn here for a 13.5-hour fast. The real length depends on your latitude and the date.
One synodic month drawn as eight lunar phases in sequence, from new moon through first quarter, full and last quarter, back to new. The Islamic calendar is lunar, which is why Ramadan moves through the solar year by about eleven days a year and why the length of the daily fast changes from one Ramadan to the next.
One synodic month. The Islamic calendar is lunar, which is why Ramadan moves through the solar year by about eleven days a year, and why the length of the daily fast changes from one Ramadan to the next.

Planned scope

Water, saliva, brushing teeth, inhalers, injections, blood tests, vomiting, eye drops, smoking and swimming, each with the position of the major schools where they differ, and each linked to its source.