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: 09-12 (100), 09-13 (100), 09-14 (100), 09-15 (100), 09-16 (100) — by astronomy; check the weather when the night is within four days.

2036-09-12astronomy score per night — click a bar for that night2036-10-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-09-12 Fri	100	—	unknown	21:10–04:50 (good, 7.67 h)	87.2° 22:50	8.24	56%	96.5°
2036-09-13 Sat	100	—	unknown	21:10–04:55 (good, 7.75 h)	87.2° 22:50	8.3	44%	103.2°
2036-09-14 Sun	100	—	unknown	21:10–04:55 (good, 7.75 h)	87.2° 22:45	8.35	34%	109.4°
2036-09-15 Mon	100	—	unknown	21:05–04:55 (good, 7.83 h)	87.2° 22:40	8.4	23%	114.7°
2036-09-16 Tue	100	—	unknown	21:05–04:55 (good, 7.83 h)	87.2° 22:35	8.45	14%	118.7°
2036-09-17 Wed	100	—	unknown	21:05–04:50 (good, 7.75 h)	87.2° 22:30	8.51	7%	120.7°
2036-09-18 Thu	100	—	unknown	21:00–04:50 (good, 7.83 h)	87.2° 22:30	8.56	2%	120.4°
2036-09-19 Fri	100	—	unknown	21:00–04:45 (good, 7.75 h)	87.2° 22:25	8.61	0%	117.9°
2036-09-20 Sat	100	—	unknown	20:55–04:40 (good, 7.75 h)	87.2° 22:20	8.66	1%	113.6°
2036-09-21 Sun	100	—	unknown	20:55–04:35 (good, 7.67 h)	87.2° 22:15	8.71	5%	107.9°
2036-09-22 Mon	100	—	unknown	20:55–04:30 (good, 7.58 h)	87.2° 22:10	8.76	11%	101.5°
2036-09-23 Tue	100	—	unknown	20:50–04:30 (good, 7.67 h)	87.2° 22:10	8.81	19%	94.7°
2036-09-24 Wed	100	—	unknown	20:50–04:25 (good, 7.58 h)	87.2° 22:05	8.86	27%	88.0°
2036-09-25 Thu	100	—	unknown	20:50–04:20 (good, 7.5 h)	87.2° 22:00	8.91	37%	81.6°
2036-09-26 Fri	100	—	unknown	20:45–04:15 (good, 7.5 h)	87.2° 21:55	8.96	47%	75.7°
2036-09-27 Sat	100	—	unknown	20:45–04:15 (good, 7.5 h)	87.2° 21:55	9.01	56%	70.4°
2036-09-28 Sun	95	—	unknown	20:40–04:10 (good, 7.5 h)	87.2° 21:50	9.06	66%	65.9°
2036-09-29 Mon	88	—	unknown	20:40–04:05 (good, 7.42 h)	87.2° 21:45	9.11	74%	62.4°
2036-09-30 Tue	82	—	unknown	20:40–04:00 (good, 7.33 h)	87.2° 21:40	9.16	82%	60.1°
2036-10-01 Wed	62	—	unknown	20:35–21:25 (good, 0.83 h)	87.2° 21:35	9.21	89%	59.2°
2036-10-02 Thu	61	—	unknown	20:35–20:50 (good, 0.25 h)	87.2° 21:35	9.25	94%	59.8°
2036-10-03 Fri	62	—	unknown	20:35–21:00 (good, 0.42 h)	87.2° 21:30	9.3	98%	61.8°
2036-10-04 Sat	65	—	unknown	20:30–21:35 (good, 1.08 h)	87.2° 21:25	9.35	100%	65.2°
2036-10-05 Sun	69	—	unknown	20:30–22:35 (good, 2.08 h)	87.2° 21:20	9.4	100%	69.7°
2036-10-06 Mon	74	—	unknown	20:30–00:10 (good, 3.67 h)	87.2° 21:15	9.44	98%	75.2°
2036-10-07 Tue	80	—	unknown	20:25–01:00 (good, 4.58 h)	87.2° 21:15	9.49	93%	81.4°
2036-10-08 Wed	100	—	unknown	20:25–02:00 (good, 5.58 h)	87.2° 21:10	9.53	87%	88.0°
2036-10-09 Thu	100	—	unknown	20:25–02:55 (good, 6.5 h)	87.2° 21:05	9.58	79%	94.8°
2036-10-10 Fri	100	—	unknown	20:20–03:00 (good, 6.67 h)	87.2° 21:00	9.63	70%	101.4°
2036-10-11 Sat	100	—	unknown	20:20–03:05 (good, 6.75 h)	87.2° 21:00	9.67	59%	107.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-09-12&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.