Coverage
2,821 of the 2,889 MICs in the ISO 10383 registry (published 2026-10-12) are answered by a Diurn calendar, in 119 countries. How each was associated matters, so it is counted separately.
| Mapped to their own calendar | 270 | An authored, checked association. |
| Through their operating MIC | 377 | A segment answered by its parent venue's calendar. |
| Through their country | 2,174 | The national calendar, where nothing more specific is mapped. |
How the days are evidenced
Every day Diurn serves carries its provenance. Across the distinct calendars, for 2026-09-05 to 2027-01-07:
| Verified | 476 | 1.7% | Read from the venue's own notice or calendar, with the source recorded. |
| Corroborated | 215 | 0.8% | From a single authoritative source, consistent with the venue's practice. |
| Inferred (predicted) | 1 | 0.0% | Computed from a rule, awaiting the announcement that settles it. |
| Inferred (advisory) | 0 | 0.0% | An approximation that can move by about a day (a moon sighting, say). |
| Inferred (definition) | 26,933 | 97.5% | A definition projected: a weekend, a fixed date, Easter. |
Most days are definitional because most days are ordinary: a weekday that is not a holiday is open by definition. The verified and corroborated days are the exceptions, which is where evidence matters.