Data Coverage
Authoritative coverage
The curated MABIMS lookup table currently covers:
2023-01-23 → 2026-12-31MABIMS month starts are set by local moon-sighting criteria, and each year (usually released in October) Kemenag issues a calendar for the next year. This coverage does not extrapolate astronomically. See every month's range laid out as a Hijri calendar.
Beyond the table: forward computation only
Requests after the table end are answered by forward computation:
mabims-computed: the Neo MABIMS criteria evaluated live at coastal observation points across Indonesia (hilal altitude ≥ 3° and elongation ≥ 6.4° at each site's local sunset on day 29; met at any single point → 29-day month). This is the same rule the curated table follows, so it stays on-method into the future. Months decided by a margin under 0.25° carry a borderline warning; but only months whose day-29 sighting evening passes the criteria by less than 0.25 deg of margin; months rejected outright never do.mabims-retro: dates below the curated table (before 2023) requireretro=true: the Neo MABIMS criteria are projected backwards down to 1945-01-01 as retrospective estimates. Since the criteria were only introduced in 2022 and curated data starts 2023, all dates below the table are pure extrapolation.
Warning: The system cannot convert dates before 2023-01-23 unless you pass
retro=true; retro data reaches back to 1945-01-01.
Hard limits
| Direction | Limit | Note |
|---|---|---|
| Backward (default) | 2023-01-23 | No conversion before this date without retro=true |
Backward (with retro=true) | 1945-01-01 | Absolute retro computation floor |
| Forward | 2100-01-01 | No conversion after this date |
Dates outside these bounds are rejected with a date_out_of_supported_range error.
Monitoring
GET /meta exposes computed_active and computed_months. The live status panel on the Demo page reads it in real time.