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: 11-29 (89), 11-30 (89), 12-01 (89), 12-02 (89), 12-03 (89) — by astronomy; check the weather when the night is within four days.

2029-11-17astronomy score per night — click a bar for that night2029-12-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-11-17 Sat	81	—	unknown	02:40–05:30 (good, 2.83 h)	42.9° 02:10	11.02	91%	68.6°
2029-11-18 Sun	45	—	unknown	23:00–05:40 (marginal, 6.67 h)	42.9° 02:05	11.05	95%	58.6°
2029-11-19 Mon	31	—	unknown	23:25–05:40 (marginal, 6.25 h)	42.9° 02:00	11.08	98%	49.1°
2029-11-20 Tue	20	—	unknown	02:10–05:15 (marginal, 3.08 h)	42.9° 01:55	11.1	100%	40.5°
2029-11-21 Wed	13	—	unknown	—	42.9° 01:55	11.13	100%	33.5°
2029-11-22 Thu	10	—	unknown	—	42.9° 01:50	11.15	97%	29.3°
2029-11-23 Fri	13	—	unknown	—	42.9° 01:45	11.17	93%	29.4°
2029-11-24 Sat	22	—	unknown	22:25–03:10 (marginal, 4.75 h)	42.9° 01:40	11.2	87%	33.9°
2029-11-25 Sun	37	—	unknown	22:00–04:45 (marginal, 6.75 h)	42.9° 01:35	11.22	80%	41.5°
2029-11-26 Mon	55	—	unknown	21:50–05:05 (marginal, 7.25 h)	42.9° 01:35	11.24	71%	50.9°
2029-11-27 Tue	80	—	unknown	22:15–03:05 (good, 4.83 h)	42.9° 01:30	11.26	61%	61.5°
2029-11-28 Wed	86	—	unknown	22:10–04:20 (good, 6.17 h)	42.9° 01:25	11.28	51%	72.8°
2029-11-29 Thu	89	—	unknown	22:05–04:25 (good, 6.33 h)	42.9° 01:20	11.3	40%	84.7°
2029-11-30 Fri	89	—	unknown	22:05–04:30 (good, 6.42 h)	42.9° 01:15	11.32	29%	97.1°
2029-12-01 Sat	89	—	unknown	22:00–04:30 (good, 6.5 h)	42.9° 01:15	11.34	19%	109.6°
2029-12-02 Sun	89	—	unknown	21:55–04:30 (good, 6.58 h)	42.9° 01:10	11.35	11%	122.1°
2029-12-03 Mon	89	—	unknown	21:50–04:25 (good, 6.58 h)	42.9° 01:05	11.37	4%	133.9°
2029-12-04 Tue	89	—	unknown	21:50–04:20 (good, 6.5 h)	42.9° 01:00	11.38	1%	144.0°
2029-12-05 Wed	89	—	unknown	21:45–04:15 (good, 6.5 h)	42.9° 01:00	11.4	0%	150.3°
2029-12-06 Thu	89	—	unknown	21:40–04:15 (good, 6.58 h)	42.9° 00:55	11.41	2%	150.4°
2029-12-07 Fri	89	—	unknown	21:35–04:10 (good, 6.58 h)	42.9° 00:50	11.42	7%	144.6°
2029-12-08 Sat	89	—	unknown	21:30–04:05 (good, 6.58 h)	42.9° 00:45	11.44	14%	135.4°
2029-12-09 Sun	89	—	unknown	21:30–04:00 (good, 6.5 h)	42.9° 00:40	11.45	23%	124.9°
2029-12-10 Mon	89	—	unknown	21:30–03:55 (good, 6.42 h)	42.9° 00:40	11.46	32%	114.0°
2029-12-11 Tue	89	—	unknown	21:30–03:55 (good, 6.42 h)	42.9° 00:35	11.47	42%	103.1°
2029-12-12 Wed	89	—	unknown	21:30–03:50 (good, 6.33 h)	42.9° 00:30	11.47	52%	92.3°
2029-12-13 Thu	87	—	unknown	21:40–03:45 (good, 6.08 h)	42.9° 00:25	11.48	61%	81.7°
2029-12-14 Fri	83	—	unknown	22:40–03:40 (good, 5.0 h)	42.9° 00:20	11.49	70%	71.4°
2029-12-15 Sat	66	—	unknown	01:15–03:05 (good, 1.83 h)	42.9° 00:20	11.49	79%	61.3°
2029-12-16 Sun	43	—	unknown	21:05–04:00 (marginal, 6.92 h)	42.9° 00:15	11.5	86%	51.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-11-17&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.