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: 11-04 (89), 11-05 (89), 11-06 (89), 11-07 (89), 11-08 (89) — by astronomy; check the weather when the night is within four days.

2045-10-29astronomy score per night — click a bar for that night2045-11-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-10-29 Sun	16	—	unknown	00:25–05:20 (marginal, 4.92 h)	42.9° 03:25	10.41	82%	32.8°
2045-10-30 Mon	27	—	unknown	23:55–05:20 (marginal, 5.42 h)	42.9° 03:20	10.44	73%	35.8°
2045-10-31 Tue	42	—	unknown	23:35–05:20 (marginal, 5.75 h)	42.9° 03:15	10.48	63%	42.7°
2045-11-01 Wed	62	—	unknown	00:25–04:35 (good, 4.17 h)	42.9° 03:10	10.52	52%	52.0°
2045-11-02 Thu	77	—	unknown	23:55–05:25 (good, 5.5 h)	42.9° 03:10	10.55	41%	62.8°
2045-11-03 Fri	86	—	unknown	23:50–05:25 (good, 5.58 h)	42.9° 03:05	10.59	30%	74.4°
2045-11-04 Sat	89	—	unknown	23:45–05:25 (good, 5.67 h)	42.9° 03:00	10.62	20%	86.3°
2045-11-05 Sun	89	—	unknown	23:40–05:25 (good, 5.75 h)	42.9° 02:55	10.66	11%	98.3°
2045-11-06 Mon	89	—	unknown	23:40–05:30 (good, 5.83 h)	42.9° 02:50	10.69	5%	110.2°
2045-11-07 Tue	89	—	unknown	23:35–05:30 (good, 5.92 h)	42.9° 02:50	10.72	1%	121.5°
2045-11-08 Wed	89	—	unknown	23:30–05:30 (good, 6.0 h)	42.9° 02:45	10.76	0%	131.7°
2045-11-09 Thu	89	—	unknown	23:25–05:30 (good, 6.08 h)	42.9° 02:40	10.79	1%	140.2°
2045-11-10 Fri	89	—	unknown	23:20–05:30 (good, 6.17 h)	42.9° 02:35	10.82	5%	145.8°
2045-11-11 Sat	89	—	unknown	23:20–05:35 (good, 6.25 h)	42.9° 02:30	10.85	10%	147.2°
2045-11-12 Sun	89	—	unknown	23:15–05:35 (good, 6.33 h)	42.9° 02:30	10.88	17%	144.4°
2045-11-13 Mon	89	—	unknown	23:10–05:35 (good, 6.42 h)	42.9° 02:25	10.91	25%	138.4°
2045-11-14 Tue	89	—	unknown	23:05–05:35 (good, 6.5 h)	42.9° 02:20	10.94	34%	130.5°
2045-11-15 Wed	89	—	unknown	23:00–05:35 (good, 6.58 h)	42.9° 02:15	10.97	43%	121.7°
2045-11-16 Thu	89	—	unknown	23:05–05:30 (good, 6.42 h)	42.9° 02:15	11.0	53%	112.3°
2045-11-17 Fri	89	—	unknown	23:05–05:30 (good, 6.42 h)	42.9° 02:10	11.03	62%	102.5°
2045-11-18 Sat	89	—	unknown	23:15–05:25 (good, 6.17 h)	42.9° 02:05	11.05	71%	92.5°
2045-11-19 Sun	88	—	unknown	23:35–05:20 (good, 5.75 h)	42.9° 02:00	11.08	79%	82.4°
2045-11-20 Mon	84	—	unknown	01:20–05:15 (good, 3.92 h)	42.9° 01:55	11.1	86%	72.1°
2045-11-21 Tue	58	—	unknown	05:05–05:10 (good, 0.08 h)	42.9° 01:55	11.13	93%	61.9°
2045-11-22 Wed	35	—	unknown	23:00–05:30 (marginal, 6.5 h)	42.9° 01:50	11.15	97%	52.1°
2045-11-23 Thu	22	—	unknown	01:20–05:05 (marginal, 3.75 h)	42.9° 01:45	11.18	99%	43.1°
2045-11-24 Fri	14	—	unknown	—	42.9° 01:40	11.2	100%	36.1°
2045-11-25 Sat	11	—	unknown	—	42.9° 01:35	11.22	97%	32.8°
2045-11-26 Sun	16	—	unknown	22:45–23:50 (marginal, 1.08 h)	42.9° 01:35	11.24	93%	34.4°
2045-11-27 Mon	28	—	unknown	22:05–04:25 (marginal, 6.33 h)	42.9° 01:30	11.26	86%	40.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-10-29&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.