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: 06-19 (100), 06-20 (100), 06-21 (100), 06-22 (100), 06-23 (100) — by astronomy; check the weather when the night is within four days.

2044-06-17astronomy score per night — click a bar for that night2044-07-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-06-17 Fri	95	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:35	4.43	58%	57.6°
2044-06-18 Sat	98	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:30	4.42	48%	58.6°
2044-06-19 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:25	4.42	37%	61.4°
2044-06-20 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:20	4.42	27%	66.0°
2044-06-21 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:20	4.42	17%	72.0°
2044-06-22 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:15	4.43	9%	79.1°
2044-06-23 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.43	4%	86.9°
2044-06-24 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:05	4.44	1%	95.1°
2044-06-25 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:00	4.45	0%	103.0°
2044-06-26 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:00	4.46	4%	110.1°
2044-06-27 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:55	4.48	9%	116.0°
2044-06-28 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 03:50	4.49	17%	120.2°
2044-06-29 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:45	4.51	26%	122.3°
2044-06-30 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:45	4.53	37%	122.3°
2044-07-01 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.55	47%	120.3°
2044-07-02 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:35	4.58	57%	116.8°
2044-07-03 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:30	4.6	67%	112.2°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-06-17&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.