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: 07-04 (100), 07-05 (100), 07-06 (100), 07-07 (100), 07-16 (100) — by astronomy; check the weather when the night is within four days.

2044-07-04astronomy score per night — click a bar for that night2044-08-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-07-04 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:25	4.63	76%	106.7°
2044-07-05 Tue	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:25	4.66	84%	100.7°
2044-07-06 Wed	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:20	4.69	90%	94.5°
2044-07-07 Thu	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:15	4.72	95%	88.1°
2044-07-08 Fri	77	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:10	4.75	98%	81.8°
2044-07-09 Sat	71	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:05	4.79	100%	75.8°
2044-07-10 Sun	63	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:05	4.82	100%	70.1°
2044-07-11 Mon	60	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:00	4.86	97%	65.2°
2044-07-12 Tue	61	—	unknown	23:05–02:20 (good, 3.25 h)	87.2° 02:55	4.9	94%	61.3°
2044-07-13 Wed	66	—	unknown	23:00–02:35 (good, 3.58 h)	87.2° 02:50	4.94	88%	58.6°
2044-07-14 Thu	94	—	unknown	23:00–03:45 (good, 4.75 h)	87.2° 02:45	4.98	81%	57.4°
2044-07-15 Fri	97	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	5.03	72%	57.9°
2044-07-16 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:40	5.07	62%	60.3°
2044-07-17 Sun	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:35	5.11	52%	64.2°
2044-07-18 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:30	5.16	41%	69.7°
2044-07-19 Tue	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:30	5.21	30%	76.2°
2044-07-20 Wed	100	—	unknown	22:55–04:10 (good, 5.25 h)	87.2° 02:25	5.26	20%	83.7°
2044-07-21 Thu	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:20	5.3	12%	91.6°
2044-07-22 Fri	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:15	5.35	5%	99.5°
2044-07-23 Sat	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:10	5.4	1%	107.1°
2044-07-24 Sun	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:10	5.45	0%	113.7°
2044-07-25 Mon	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:05	5.51	2%	118.7°
2044-07-26 Tue	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:00	5.56	7%	121.8°
2044-07-27 Wed	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:55	5.61	14%	122.7°
2044-07-28 Thu	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:50	5.67	22%	121.4°
2044-07-29 Fri	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:50	5.72	32%	118.3°
2044-07-30 Sat	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:45	5.77	42%	113.8°
2044-07-31 Sun	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:40	5.83	52%	108.5°
2044-08-01 Mon	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:35	5.88	62%	102.5°
2044-08-02 Tue	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.2° 01:35	5.94	71%	96.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-07-04&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.