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: 07-05 (100), 07-06 (100), 07-07 (100), 07-08 (100), 07-09 (100) — by astronomy; check the weather when the night is within four days.

2030-07-05astronomy score per night — click a bar for that night2030-08-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-07-05 Fri	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:25	4.64	24%	127.7°
2030-07-06 Sat	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:20	4.67	34%	126.1°
2030-07-07 Sun	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:15	4.7	44%	122.4°
2030-07-08 Mon	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:15	4.73	55%	116.8°
2030-07-09 Tue	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:10	4.77	66%	109.6°
2030-07-10 Wed	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:05	4.8	77%	101.4°
2030-07-11 Thu	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:00	4.84	86%	92.6°
2030-07-12 Fri	80	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 02:55	4.88	93%	83.6°
2030-07-13 Sat	72	—	unknown	23:00–03:55 (good, 4.92 h)	87.2° 02:55	4.92	98%	74.8°
2030-07-14 Sun	59	—	unknown	23:40–04:00 (good, 4.33 h)	87.2° 02:50	4.96	100%	66.7°
2030-07-15 Mon	51	—	unknown	23:00–04:00 (marginal, 5.0 h)	87.2° 02:45	5.0	99%	60.0°
2030-07-16 Tue	50	—	unknown	23:00–04:00 (marginal, 5.0 h)	87.2° 02:40	5.04	95%	55.2°
2030-07-17 Wed	56	—	unknown	22:55–00:35 (good, 1.67 h)	87.2° 02:40	5.09	89%	52.7°
2030-07-18 Thu	66	—	unknown	22:55–01:50 (good, 2.92 h)	87.2° 02:35	5.13	82%	52.6°
2030-07-19 Fri	95	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:30	5.18	73%	54.8°
2030-07-20 Sat	99	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:25	5.23	64%	58.8°
2030-07-21 Sun	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:20	5.27	54%	64.1°
2030-07-22 Mon	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:20	5.32	44%	70.3°
2030-07-23 Tue	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:15	5.37	35%	77.0°
2030-07-24 Wed	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.2° 02:10	5.42	26%	84.0°
2030-07-25 Thu	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:05	5.48	18%	91.3°
2030-07-26 Fri	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:00	5.53	12%	98.5°
2030-07-27 Sat	100	—	unknown	22:45–04:20 (good, 5.58 h)	87.2° 02:00	5.58	6%	105.5°
2030-07-28 Sun	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:55	5.63	2%	112.2°
2030-07-29 Mon	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:50	5.69	0%	118.1°
2030-07-30 Tue	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:45	5.74	0%	123.0°
2030-07-31 Wed	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:45	5.79	2%	126.3°
2030-08-01 Thu	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:40	5.85	7%	127.6°
2030-08-02 Fri	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:35	5.9	13%	126.5°
2030-08-03 Sat	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.2° 01:30	5.96	21%	123.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-07-05&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.