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: 11-25 (50), 11-26 (49), 11-27 (49), 11-28 (48), 11-29 (46) — by astronomy; check the weather when the night is within four days.

2037-11-25astronomy score per night — click a bar for that night2037-12-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-11-25 Wed	50	—	unknown	18:35–20:30 (good, 1.92 h)	87.1° 14:40	11.22	91%	119.1°
2037-11-26 Thu	49	—	unknown	18:35–20:30 (good, 1.92 h)	87.1° 14:35	11.24	84%	117.8°
2037-11-27 Fri	49	—	unknown	18:35–20:30 (good, 1.92 h)	87.1° 14:30	11.26	75%	114.9°
2037-11-28 Sat	48	—	unknown	18:35–20:30 (good, 1.92 h)	87.1° 14:30	11.28	65%	110.5°
2037-11-29 Sun	46	—	unknown	18:35–20:25 (good, 1.83 h)	87.1° 14:25	11.3	54%	105.0°
2037-11-30 Mon	44	—	unknown	18:35–20:20 (good, 1.75 h)	87.1° 14:20	11.32	42%	98.7°
2037-12-01 Tue	42	—	unknown	18:35–20:15 (good, 1.67 h)	87.1° 14:15	11.34	31%	91.9°
2037-12-02 Wed	41	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:15	11.35	21%	84.9°
2037-12-03 Thu	40	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:10	11.37	12%	78.1°
2037-12-04 Fri	38	—	unknown	18:35–20:05 (good, 1.5 h)	87.1° 14:05	11.38	6%	72.0°
2037-12-05 Sat	37	—	unknown	18:35–20:00 (good, 1.42 h)	87.1° 14:00	11.4	2%	66.8°
2037-12-06 Sun	36	—	unknown	18:35–19:55 (good, 1.33 h)	87.1° 13:55	11.41	0%	63.1°
2037-12-07 Mon	34	—	unknown	18:35–19:50 (good, 1.25 h)	87.1° 13:55	11.42	1%	61.2°
2037-12-08 Tue	32	—	unknown	18:35–19:50 (good, 1.25 h)	87.1° 13:50	11.44	5%	61.1°
2037-12-09 Wed	29	—	unknown	18:35–19:45 (good, 1.17 h)	87.1° 13:45	11.45	10%	62.6°
2037-12-10 Thu	26	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 13:40	11.46	17%	65.7°
2037-12-11 Fri	24	—	unknown	18:35–19:30 (good, 0.92 h)	87.1° 13:35	11.47	25%	69.8°
2037-12-12 Sat	21	—	unknown	18:35–19:20 (good, 0.75 h)	87.1° 13:35	11.47	34%	74.6°
2037-12-13 Sun	19	—	unknown	18:35–19:10 (good, 0.58 h)	87.1° 13:30	11.48	44%	80.0°
2037-12-14 Mon	17	—	unknown	18:35–19:05 (good, 0.5 h)	87.1° 13:25	11.49	53%	85.6°
2037-12-15 Tue	15	—	unknown	18:35–19:00 (good, 0.42 h)	87.1° 13:20	11.49	62%	91.3°
2037-12-16 Wed	15	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 13:15	11.5	71%	97.0°
2037-12-17 Thu	14	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:15	11.5	79%	102.6°
2037-12-18 Fri	14	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:10	11.5	87%	107.7°
2037-12-19 Sat	14	—	unknown	18:35–18:45 (good, 0.17 h)	87.1° 13:05	11.51	93%	112.2°
2037-12-20 Sun	14	—	unknown	18:35–18:45 (good, 0.17 h)	87.1° 13:00	11.51	97%	115.9°
2037-12-21 Mon	12	—	unknown	18:35–18:45 (good, 0.17 h)	87.1° 13:00	11.51	100%	118.3°
2037-12-22 Tue	12	—	unknown	18:35–18:40 (good, 0.08 h)	87.1° 12:55	11.51	100%	119.1°
2037-12-23 Wed	10	—	unknown	18:05–19:20 (marginal, 1.25 h)	87.1° 12:50	11.5	98%	118.2°
2037-12-24 Thu	11	—	unknown	18:40–18:45 (good, 0.08 h)	87.1° 12:45	11.5	94%	115.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-11-25&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.