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: 11-16 (89), 11-17 (89), 11-18 (89), 11-19 (89), 11-20 (89) — by astronomy; check the weather when the night is within four days.

2033-11-05astronomy score per night — click a bar for that night2033-12-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2033-11-18 Fri	89	—	unknown	22:50–05:25 (good, 6.58 h)	42.9° 02:05	11.05	9%	116.1°
2033-11-19 Sat	89	—	unknown	22:45–05:20 (good, 6.58 h)	42.9° 02:00	11.08	4%	126.5°
2033-11-20 Sun	89	—	unknown	22:45–05:15 (good, 6.5 h)	42.9° 01:55	11.1	1%	136.6°
2033-11-21 Mon	89	—	unknown	22:40–05:10 (good, 6.5 h)	42.9° 01:55	11.13	0%	145.8°
2033-11-22 Tue	89	—	unknown	22:35–05:10 (good, 6.58 h)	42.9° 01:50	11.15	1%	153.0°
2033-11-23 Wed	89	—	unknown	22:30–05:05 (good, 6.58 h)	42.9° 01:45	11.17	4%	156.2°
2033-11-24 Thu	89	—	unknown	22:25–05:00 (good, 6.58 h)	42.9° 01:40	11.2	8%	153.6°
2033-11-25 Fri	89	—	unknown	22:25–04:55 (good, 6.5 h)	42.9° 01:35	11.22	14%	146.3°
2033-11-26 Sat	89	—	unknown	22:20–04:50 (good, 6.5 h)	42.9° 01:35	11.24	22%	136.5°
2033-11-27 Sun	89	—	unknown	22:15–04:50 (good, 6.58 h)	42.9° 01:30	11.26	32%	125.4°
2033-11-28 Mon	89	—	unknown	22:15–04:45 (good, 6.5 h)	42.9° 01:25	11.28	42%	113.5°
2033-11-29 Tue	89	—	unknown	22:20–04:40 (good, 6.33 h)	42.9° 01:20	11.3	53%	101.1°
2033-11-30 Wed	89	—	unknown	22:25–04:35 (good, 6.17 h)	42.9° 01:15	11.32	64%	88.3°
2033-12-01 Thu	87	—	unknown	23:10–04:35 (good, 5.42 h)	42.9° 01:15	11.34	75%	75.2°
2033-12-02 Fri	81	—	unknown	02:00–04:30 (good, 2.5 h)	42.9° 01:10	11.35	84%	62.0°
2033-12-03 Sat	39	—	unknown	22:05–04:50 (marginal, 6.75 h)	42.9° 01:05	11.37	92%	49.2°
2033-12-04 Sun	22	—	unknown	00:45–04:25 (marginal, 3.67 h)	42.9° 01:00	11.38	97%	37.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-11-05&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.