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: 09-26 (100), 09-27 (100), 09-28 (100), 09-29 (100), 09-30 (100) — by astronomy; check the weather when the night is within four days.

2029-09-23astronomy score per night — click a bar for that night2029-10-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-09-23 Sun	63	—	unknown	20:50–21:20 (good, 0.5 h)	87.2° 22:10	8.8	98%	59.5°
2029-09-24 Mon	68	—	unknown	20:50–22:35 (good, 1.75 h)	87.2° 22:05	8.85	95%	64.6°
2029-09-25 Tue	74	—	unknown	20:50–00:35 (good, 3.75 h)	87.2° 22:00	8.9	91%	70.6°
2029-09-26 Wed	100	—	unknown	20:45–01:45 (good, 5.0 h)	87.2° 21:55	8.95	84%	77.2°
2029-09-27 Thu	100	—	unknown	20:45–02:55 (good, 6.17 h)	87.2° 21:55	9.0	77%	84.2°
2029-09-28 Fri	100	—	unknown	20:45–03:40 (good, 6.92 h)	87.2° 21:50	9.05	69%	91.5°
2029-09-29 Sat	100	—	unknown	20:40–03:45 (good, 7.08 h)	87.2° 21:45	9.1	59%	98.7°
2029-09-30 Sun	100	—	unknown	20:40–03:50 (good, 7.17 h)	87.2° 21:40	9.14	50%	105.9°
2029-10-01 Mon	100	—	unknown	20:35–03:50 (good, 7.25 h)	87.2° 21:40	9.19	39%	112.7°
2029-10-02 Tue	100	—	unknown	20:35–03:50 (good, 7.25 h)	87.2° 21:35	9.24	29%	118.8°
2029-10-03 Wed	100	—	unknown	20:35–03:50 (good, 7.25 h)	87.2° 21:30	9.29	20%	123.7°
2029-10-04 Thu	100	—	unknown	20:30–03:45 (good, 7.25 h)	87.2° 21:25	9.34	12%	126.7°
2029-10-05 Fri	100	—	unknown	20:30–03:40 (good, 7.17 h)	87.2° 21:20	9.38	5%	127.1°
2029-10-06 Sat	100	—	unknown	20:30–03:40 (good, 7.17 h)	87.2° 21:20	9.43	1%	124.8°
2029-10-07 Sun	100	—	unknown	20:25–03:35 (good, 7.17 h)	87.2° 21:15	9.48	0%	119.8°
2029-10-08 Mon	100	—	unknown	20:25–03:30 (good, 7.08 h)	87.2° 21:10	9.52	2%	112.9°
2029-10-09 Tue	100	—	unknown	20:25–03:25 (good, 7.0 h)	87.2° 21:05	9.57	7%	104.7°
2029-10-10 Wed	100	—	unknown	20:20–03:20 (good, 7.0 h)	87.2° 21:00	9.61	14%	96.0°
2029-10-11 Thu	100	—	unknown	20:20–03:20 (good, 7.0 h)	87.2° 21:00	9.66	23%	87.1°
2029-10-12 Fri	100	—	unknown	20:20–03:15 (good, 6.92 h)	87.2° 20:55	9.7	33%	78.7°
2029-10-13 Sat	100	—	unknown	20:20–03:10 (good, 6.83 h)	87.2° 20:50	9.75	44%	70.9°
2029-10-14 Sun	93	—	unknown	20:15–03:05 (good, 6.83 h)	87.2° 20:45	9.79	55%	64.2°
2029-10-15 Mon	86	—	unknown	20:15–03:05 (good, 6.83 h)	87.2° 20:45	9.83	65%	58.7°
2029-10-16 Tue	70	—	unknown	20:15–02:25 (good, 6.17 h)	87.2° 20:40	9.88	74%	54.9°
2029-10-17 Wed	58	—	unknown	20:10–03:30 (marginal, 7.33 h)	87.2° 20:35	9.92	82%	52.9°
2029-10-18 Thu	51	—	unknown	20:10–03:15 (marginal, 7.08 h)	87.2° 20:30	9.96	89%	52.9°
2029-10-19 Fri	46	—	unknown	20:10–03:00 (marginal, 6.83 h)	87.2° 20:25	10.0	94%	54.8°
2029-10-20 Sat	47	—	unknown	20:05–02:45 (marginal, 6.67 h)	87.2° 20:25	10.05	98%	58.3°
2029-10-21 Sun	52	—	unknown	20:05–20:10 (good, 0.08 h)	87.2° 20:20	10.09	100%	63.2°
2029-10-22 Mon	61	—	unknown	20:05–21:20 (good, 1.25 h)	87.2° 20:15	10.13	100%	69.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-09-23&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.