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 North America Nebula: 10-09 (100), 10-10 (100), 10-11 (100), 10-12 (100), 10-13 (100) — by astronomy; check the weather when the night is within four days.

2045-10-09astronomy score per night — click a bar for that night2045-11-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-10-09 Mon	100	—	unknown	20:25–03:25 (good, 7.0 h)	87.2° 21:05	9.57	0%	121.2°
2045-10-10 Tue	100	—	unknown	20:20–03:25 (good, 7.08 h)	87.1° 21:00	9.62	0%	116.4°
2045-10-11 Wed	100	—	unknown	20:20–03:20 (good, 7.0 h)	87.2° 21:00	9.66	3%	110.2°
2045-10-12 Thu	100	—	unknown	20:20–03:15 (good, 6.92 h)	87.2° 20:55	9.71	8%	103.2°
2045-10-13 Fri	100	—	unknown	20:15–03:10 (good, 6.92 h)	87.2° 20:50	9.75	15%	95.8°
2045-10-14 Sat	100	—	unknown	20:15–03:05 (good, 6.83 h)	87.2° 20:45	9.79	23%	88.5°
2045-10-15 Sun	100	—	unknown	20:15–03:05 (good, 6.83 h)	87.2° 20:45	9.84	32%	81.4°
2045-10-16 Mon	100	—	unknown	20:15–03:00 (good, 6.75 h)	87.2° 20:40	9.88	42%	74.8°
2045-10-17 Tue	96	—	unknown	20:10–02:55 (good, 6.75 h)	87.2° 20:35	9.92	51%	68.8°
2045-10-18 Wed	88	—	unknown	20:10–02:50 (good, 6.67 h)	87.2° 20:30	9.97	61%	63.7°
2045-10-19 Thu	81	—	unknown	20:10–02:45 (good, 6.58 h)	87.2° 20:25	10.01	70%	59.6°
2045-10-20 Fri	63	—	unknown	20:05–00:45 (good, 4.67 h)	87.2° 20:25	10.05	78%	56.8°
2045-10-21 Sat	58	—	unknown	20:05–03:10 (marginal, 7.08 h)	87.2° 20:20	10.09	85%	55.6°
2045-10-22 Sun	51	—	unknown	20:05–02:55 (marginal, 6.83 h)	87.2° 20:15	10.13	91%	56.1°
2045-10-23 Mon	47	—	unknown	20:05–02:40 (marginal, 6.58 h)	87.2° 20:10	10.17	96%	58.3°
2045-10-24 Tue	50	—	unknown	20:00–02:30 (marginal, 6.5 h)	87.1° 20:05	10.21	99%	62.1°
2045-10-25 Wed	56	—	unknown	20:00–20:40 (good, 0.67 h)	87.2° 20:05	10.25	100%	67.2°
2045-10-26 Thu	66	—	unknown	20:00–22:10 (good, 2.17 h)	87.2° 20:00	10.29	99%	73.4°
2045-10-27 Fri	75	—	unknown	20:00–23:30 (good, 3.5 h)	87.2° 19:55	10.33	95%	80.4°
2045-10-28 Sat	82	—	unknown	19:55–00:35 (good, 4.67 h)	87.2° 19:50	10.37	90%	87.8°
2045-10-29 Sun	100	—	unknown	18:55–00:35 (good, 5.67 h)	87.2° 18:50	10.41	82%	95.5°
2045-10-30 Mon	100	—	unknown	18:55–00:45 (good, 5.83 h)	87.2° 18:45	10.44	73%	103.0°
2045-10-31 Tue	100	—	unknown	18:55–00:50 (good, 5.92 h)	87.2° 18:40	10.48	63%	110.1°
2045-11-01 Wed	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:35	10.52	52%	116.2°
2045-11-02 Thu	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:30	10.55	41%	121.0°
2045-11-03 Fri	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:30	10.59	30%	123.9°
2045-11-04 Sat	100	—	unknown	18:50–00:45 (good, 5.92 h)	87.2° 18:25	10.62	20%	124.5°
2045-11-05 Sun	100	—	unknown	18:50–00:40 (good, 5.83 h)	87.2° 18:20	10.66	11%	122.6°
2045-11-06 Mon	100	—	unknown	18:45–00:35 (good, 5.83 h)	87.2° 18:15	10.69	5%	118.6°
2045-11-07 Tue	100	—	unknown	18:45–00:35 (good, 5.83 h)	87.1° 18:10	10.72	1%	112.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-10-09&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.