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: 07-27 (100), 07-28 (100), 07-29 (100), 07-30 (100), 07-31 (100) — by astronomy; check the weather when the night is within four days.

2043-07-26astronomy score per night — click a bar for that night2043-08-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-07-26 Sun	99	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:05	5.52	76%	60.3°
2043-07-27 Mon	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:00	5.57	66%	63.3°
2043-07-28 Tue	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:55	5.62	55%	67.9°
2043-07-29 Wed	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:50	5.68	43%	73.8°
2043-07-30 Thu	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:50	5.73	32%	80.6°
2043-07-31 Fri	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:45	5.79	22%	87.9°
2043-08-01 Sat	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:40	5.84	13%	95.2°
2043-08-02 Sun	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:35	5.9	6%	102.4°
2043-08-03 Mon	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.2° 01:30	5.95	2%	108.8°
2043-08-04 Tue	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.2° 01:30	6.01	0%	114.2°
2043-08-05 Wed	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.2° 01:25	6.06	1%	118.2°
2043-08-06 Thu	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.2° 01:20	6.12	4%	120.5°
2043-08-07 Fri	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.2° 01:15	6.18	9%	120.9°
2043-08-08 Sat	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.2° 01:10	6.23	16%	119.7°
2043-08-09 Sun	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.2° 01:10	6.29	24%	117.0°
2043-08-10 Mon	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.2° 01:05	6.35	33%	113.1°
2043-08-11 Tue	100	—	unknown	22:15–04:40 (good, 6.42 h)	87.2° 01:00	6.41	42%	108.3°
2043-08-12 Wed	100	—	unknown	22:15–04:45 (good, 6.5 h)	87.2° 00:55	6.46	51%	102.9°
2043-08-13 Thu	100	—	unknown	22:15–04:45 (good, 6.5 h)	87.2° 00:50	6.52	61%	97.1°
2043-08-14 Fri	100	—	unknown	22:10–04:45 (good, 6.58 h)	87.2° 00:50	6.58	70%	91.0°
2043-08-15 Sat	100	—	unknown	22:10–04:45 (good, 6.58 h)	87.2° 00:45	6.64	78%	84.8°
2043-08-16 Sun	100	—	unknown	22:05–04:50 (good, 6.75 h)	87.2° 00:40	6.69	86%	78.7°
2043-08-17 Mon	98	—	unknown	22:05–04:50 (good, 6.75 h)	87.2° 00:35	6.75	92%	72.9°
2043-08-18 Tue	90	—	unknown	22:05–04:50 (good, 6.75 h)	87.2° 00:35	6.81	97%	67.6°
2043-08-19 Wed	64	—	unknown	02:30–04:45 (good, 2.25 h)	87.2° 00:30	6.87	99%	63.3°
2043-08-20 Thu	64	—	unknown	22:00–22:55 (good, 0.92 h)	87.2° 00:25	6.92	100%	60.3°
2043-08-21 Fri	66	—	unknown	21:55–23:10 (good, 1.25 h)	87.2° 00:20	6.98	98%	59.0°
2043-08-22 Sat	69	—	unknown	21:55–23:50 (good, 1.92 h)	87.2° 00:15	7.04	94%	59.7°
2043-08-23 Sun	74	—	unknown	21:55–01:10 (good, 3.25 h)	87.2° 00:15	7.1	87%	62.3°
2043-08-24 Mon	100	—	unknown	21:50–03:20 (good, 5.5 h)	87.2° 00:10	7.15	78%	66.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-07-26&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.