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 Vega: 07-30 (100), 07-31 (100), 08-01 (100), 08-02 (100), 08-03 (100) — by astronomy; check the weather when the night is within four days.

2037-07-28astronomy score per night — click a bar for that night2037-08-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-07-28 Tue	72	—	unknown	22:40–02:40 (good, 4.0 h)	87.1° 23:30	5.65	97%	71.2°
2037-07-29 Wed	77	—	unknown	22:40–03:15 (good, 4.58 h)	87.1° 23:30	5.7	93%	76.3°
2037-07-30 Thu	100	—	unknown	22:35–03:55 (good, 5.33 h)	87.1° 23:25	5.76	87%	81.9°
2037-07-31 Fri	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:20	5.81	80%	87.7°
2037-08-01 Sat	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:15	5.87	72%	93.6°
2037-08-02 Sun	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:10	5.92	63%	99.4°
2037-08-03 Mon	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:10	5.98	54%	105.0°
2037-08-04 Tue	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:05	6.03	44%	110.1°
2037-08-05 Wed	100	—	unknown	22:25–04:30 (good, 6.08 h)	87.1° 23:00	6.09	34%	114.4°
2037-08-06 Thu	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.15	25%	117.8°
2037-08-07 Fri	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.2	16%	119.6°
2037-08-08 Sat	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.1° 22:50	6.26	9%	119.7°
2037-08-09 Sun	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:45	6.32	3%	117.8°
2037-08-10 Mon	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:40	6.37	0%	114.0°
2037-08-11 Tue	100	—	unknown	22:15–04:35 (good, 6.33 h)	87.1° 22:35	6.43	0%	108.6°
2037-08-12 Wed	100	—	unknown	22:15–04:30 (good, 6.25 h)	87.1° 22:35	6.49	3%	102.1°
2037-08-13 Thu	100	—	unknown	22:10–04:30 (good, 6.33 h)	87.1° 22:30	6.55	9%	94.9°
2037-08-14 Fri	100	—	unknown	22:10–04:25 (good, 6.25 h)	87.1° 22:25	6.6	17%	87.5°
2037-08-15 Sat	100	—	unknown	22:10–04:20 (good, 6.17 h)	87.1° 22:20	6.66	27%	80.4°
2037-08-16 Sun	100	—	unknown	22:05–04:15 (good, 6.17 h)	87.1° 22:15	6.72	38%	73.9°
2037-08-17 Mon	100	—	unknown	22:05–04:10 (good, 6.08 h)	87.1° 22:15	6.78	49%	68.4°
2037-08-18 Tue	100	—	unknown	22:00–04:10 (good, 6.17 h)	87.1° 22:10	6.83	60%	64.2°
2037-08-19 Wed	94	—	unknown	22:00–04:05 (good, 6.08 h)	87.1° 22:05	6.89	70%	61.4°
2037-08-20 Thu	88	—	unknown	22:00–04:00 (good, 6.0 h)	87.1° 22:00	6.95	79%	60.2°
2037-08-21 Fri	82	—	unknown	21:55–03:55 (good, 6.0 h)	87.1° 21:55	7.01	86%	60.6°
2037-08-22 Sat	63	—	unknown	21:55–01:35 (good, 3.67 h)	87.1° 21:55	7.06	92%	62.5°
2037-08-23 Sun	62	—	unknown	21:55–00:45 (good, 2.83 h)	87.1° 21:50	7.12	97%	65.7°
2037-08-24 Mon	64	—	unknown	21:50–00:40 (good, 2.83 h)	87.1° 21:45	7.18	99%	69.9°
2037-08-25 Tue	69	—	unknown	21:50–00:55 (good, 3.08 h)	87.1° 21:40	7.24	100%	74.8°
2037-08-26 Wed	74	—	unknown	21:45–01:20 (good, 3.58 h)	87.1° 21:40	7.29	99%	80.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-07-28&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.