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: 09-30 (100), 10-01 (100), 10-02 (100), 10-03 (100), 10-04 (100) — by astronomy; check the weather when the night is within four days.

2034-09-26astronomy score per night — click a bar for that night2034-10-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-09-26 Tue	58	—	unknown	20:45–04:40 (marginal, 7.92 h)	87.2° 22:00	8.94	98%	57.3°
2034-09-27 Wed	62	—	unknown	20:45–21:05 (good, 0.33 h)	87.2° 21:55	8.99	100%	61.0°
2034-09-28 Thu	67	—	unknown	20:45–22:25 (good, 1.67 h)	87.2° 21:50	9.04	99%	66.6°
2034-09-29 Fri	75	—	unknown	20:40–00:35 (good, 3.92 h)	87.2° 21:45	9.09	95%	73.6°
2034-09-30 Sat	100	—	unknown	20:40–01:45 (good, 5.08 h)	87.2° 21:45	9.13	89%	81.4°
2034-10-01 Sun	100	—	unknown	20:40–03:00 (good, 6.33 h)	87.2° 21:40	9.18	80%	89.6°
2034-10-02 Mon	100	—	unknown	20:35–03:30 (good, 6.92 h)	87.2° 21:35	9.23	70%	97.7°
2034-10-03 Tue	100	—	unknown	20:35–03:35 (good, 7.0 h)	87.2° 21:30	9.28	59%	105.3°
2034-10-04 Wed	100	—	unknown	20:35–03:40 (good, 7.08 h)	87.2° 21:25	9.33	48%	112.1°
2034-10-05 Thu	100	—	unknown	20:30–03:40 (good, 7.17 h)	87.2° 21:25	9.37	37%	117.6°
2034-10-06 Fri	100	—	unknown	20:30–03:35 (good, 7.08 h)	87.2° 21:20	9.42	27%	121.6°
2034-10-07 Sat	100	—	unknown	20:30–03:35 (good, 7.08 h)	87.2° 21:15	9.47	18%	123.8°
2034-10-08 Sun	100	—	unknown	20:25–03:30 (good, 7.08 h)	87.2° 21:10	9.51	11%	124.0°
2034-10-09 Mon	100	—	unknown	20:25–03:25 (good, 7.0 h)	87.2° 21:05	9.56	6%	122.3°
2034-10-10 Tue	100	—	unknown	20:25–03:25 (good, 7.0 h)	87.2° 21:05	9.6	2%	119.0°
2034-10-11 Wed	100	—	unknown	20:20–03:20 (good, 7.0 h)	87.2° 21:00	9.65	0%	114.5°
2034-10-12 Thu	100	—	unknown	20:20–03:15 (good, 6.92 h)	87.2° 20:55	9.69	0%	109.0°
2034-10-13 Fri	100	—	unknown	20:20–03:10 (good, 6.83 h)	87.2° 20:50	9.74	2%	102.9°
2034-10-14 Sat	100	—	unknown	20:15–03:10 (good, 6.92 h)	87.2° 20:50	9.78	6%	96.4°
2034-10-15 Sun	100	—	unknown	20:15–03:05 (good, 6.83 h)	87.2° 20:45	9.82	12%	89.8°
2034-10-16 Mon	100	—	unknown	20:15–03:00 (good, 6.75 h)	87.2° 20:40	9.87	18%	83.2°
2034-10-17 Tue	100	—	unknown	20:10–02:55 (good, 6.75 h)	87.2° 20:35	9.91	26%	76.8°
2034-10-18 Wed	100	—	unknown	20:10–02:50 (good, 6.67 h)	87.2° 20:30	9.95	35%	70.8°
2034-10-19 Thu	97	—	unknown	20:10–02:50 (good, 6.67 h)	87.2° 20:30	9.99	44%	65.4°
2034-10-20 Fri	90	—	unknown	20:05–02:45 (good, 6.67 h)	87.2° 20:25	10.04	54%	60.8°
2034-10-21 Sat	83	—	unknown	20:05–02:40 (good, 6.58 h)	87.2° 20:20	10.08	64%	57.6°
2034-10-22 Sun	65	—	unknown	20:05–02:00 (good, 5.92 h)	87.2° 20:15	10.12	74%	56.0°
2034-10-23 Mon	60	—	unknown	20:05–20:15 (good, 0.17 h)	87.2° 20:10	10.16	83%	56.5°
2034-10-24 Tue	56	—	unknown	20:00–02:50 (marginal, 6.83 h)	87.2° 20:10	10.2	90%	59.1°
2034-10-25 Wed	55	—	unknown	20:00–20:15 (good, 0.25 h)	87.2° 20:05	10.24	96%	63.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-09-26&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.