Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for Great Orion Nebula: 10-19 (89), 10-20 (89), 10-21 (89), 10-22 (89), 10-23 (89) — by astronomy; check the weather when the night is within four days.

2033-10-19astronomy score per night — click a bar for that night2033-11-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-10-19 Wed	89	—	unknown	01:50–06:10 (good, 4.33 h)	42.9° 05:05	10.0	10%	86.6°
2033-10-20 Thu	89	—	unknown	01:45–06:10 (good, 4.42 h)	42.9° 05:00	10.05	5%	97.5°
2033-10-21 Fri	89	—	unknown	01:40–06:10 (good, 4.5 h)	42.9° 04:55	10.09	2%	108.2°
2033-10-22 Sat	89	—	unknown	01:35–06:10 (good, 4.58 h)	42.9° 04:50	10.13	0%	118.9°
2033-10-23 Sun	89	—	unknown	01:35–06:15 (good, 4.67 h)	42.9° 04:45	10.17	0%	129.2°
2033-10-24 Mon	89	—	unknown	01:30–06:15 (good, 4.75 h)	42.9° 04:45	10.21	2%	139.1°
2033-10-25 Tue	89	—	unknown	01:25–06:15 (good, 4.83 h)	42.9° 04:40	10.25	6%	147.9°
2033-10-26 Wed	89	—	unknown	01:20–06:15 (good, 4.92 h)	42.9° 04:35	10.29	12%	154.3°
2033-10-27 Thu	89	—	unknown	01:15–06:15 (good, 5.0 h)	42.9° 04:30	10.33	19%	156.2°
2033-10-28 Fri	89	—	unknown	01:15–06:20 (good, 5.08 h)	42.9° 04:25	10.36	27%	152.4°
2033-10-29 Sat	89	—	unknown	01:10–05:20 (good, 5.17 h)	42.9° 03:25	10.4	37%	144.4°
2033-10-30 Sun	89	—	unknown	00:05–05:20 (good, 5.25 h)	42.9° 03:20	10.44	47%	134.2°
2033-10-31 Mon	89	—	unknown	00:05–05:20 (good, 5.25 h)	42.9° 03:15	10.48	58%	122.6°
2033-11-01 Tue	89	—	unknown	00:10–05:25 (good, 5.25 h)	42.9° 03:10	10.51	69%	110.3°
2033-11-02 Wed	89	—	unknown	00:15–05:25 (good, 5.17 h)	42.9° 03:10	10.55	79%	97.3°
2033-11-03 Thu	88	—	unknown	00:50–05:25 (good, 4.58 h)	42.9° 03:05	10.58	88%	83.9°
2033-11-04 Fri	78	—	unknown	03:05–05:25 (good, 2.33 h)	42.9° 03:00	10.62	94%	70.3°
2033-11-05 Sat	39	—	unknown	23:55–05:25 (marginal, 5.5 h)	42.9° 02:55	10.65	99%	56.7°
2033-11-06 Sun	24	—	unknown	01:20–05:30 (marginal, 4.17 h)	42.9° 02:50	10.69	100%	43.9°
2033-11-07 Mon	14	—	unknown	04:20–05:30 (marginal, 1.17 h)	42.9° 02:50	10.72	98%	32.6°
2033-11-08 Tue	13	—	unknown	—	42.9° 02:45	10.75	94%	25.1°
2033-11-09 Wed	17	—	unknown	23:45–02:20 (marginal, 2.58 h)	42.9° 02:40	10.79	87%	24.5°
2033-11-10 Thu	26	—	unknown	23:10–05:30 (marginal, 6.33 h)	42.9° 02:35	10.82	79%	30.7°
2033-11-11 Fri	43	—	unknown	22:50–05:35 (marginal, 6.75 h)	42.9° 02:30	10.85	69%	40.1°
2033-11-12 Sat	63	—	unknown	23:45–02:50 (good, 3.08 h)	42.9° 02:30	10.88	59%	50.8°
2033-11-13 Sun	81	—	unknown	23:10–05:05 (good, 5.92 h)	42.9° 02:25	10.91	49%	61.8°
2033-11-14 Mon	85	—	unknown	23:05–05:20 (good, 6.25 h)	42.9° 02:20	10.94	40%	72.8°
2033-11-15 Tue	88	—	unknown	23:00–05:25 (good, 6.42 h)	42.9° 02:15	10.97	30%	83.7°
2033-11-16 Wed	89	—	unknown	23:00–05:25 (good, 6.42 h)	42.9° 02:10	11.0	22%	94.6°
2033-11-17 Thu	89	—	unknown	22:55–05:25 (good, 6.5 h)	42.9° 02:10	11.02	15%	105.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-10-19&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.