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: 11-23 (55), 11-22 (54), 11-24 (54), 11-25 (52), 11-26 (50) — by astronomy; check the weather when the night is within four days.

2040-11-22astronomy score per night — click a bar for that night2040-12-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2040-11-22 Thu	54	—	unknown	18:35–20:40 (good, 2.08 h)	87.1° 14:50	11.16	84%	114.0°
2040-11-23 Fri	55	—	unknown	18:35–20:45 (good, 2.17 h)	87.1° 14:45	11.18	76%	112.5°
2040-11-24 Sat	54	—	unknown	18:35–20:40 (good, 2.08 h)	87.1° 14:45	11.2	68%	110.1°
2040-11-25 Sun	52	—	unknown	18:35–20:40 (good, 2.08 h)	87.1° 14:40	11.23	59%	106.8°
2040-11-26 Mon	50	—	unknown	18:35–20:35 (good, 2.0 h)	87.1° 14:35	11.25	50%	102.8°
2040-11-27 Tue	48	—	unknown	18:35–20:30 (good, 1.92 h)	87.1° 14:30	11.27	40%	98.2°
2040-11-28 Wed	47	—	unknown	18:35–20:25 (good, 1.83 h)	87.1° 14:25	11.29	31%	93.3°
2040-11-29 Thu	46	—	unknown	18:35–20:25 (good, 1.83 h)	87.1° 14:25	11.31	22%	88.1°
2040-11-30 Fri	44	—	unknown	18:35–20:20 (good, 1.75 h)	87.1° 14:20	11.32	14%	82.8°
2040-12-01 Sat	42	—	unknown	18:35–20:15 (good, 1.67 h)	87.1° 14:15	11.34	7%	77.7°
2040-12-02 Sun	41	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:10	11.36	2%	73.0°
2040-12-03 Mon	40	—	unknown	18:35–20:05 (good, 1.5 h)	87.1° 14:10	11.37	0%	69.2°
2040-12-04 Tue	38	—	unknown	18:35–20:05 (good, 1.5 h)	87.1° 14:05	11.39	1%	66.6°
2040-12-05 Wed	36	—	unknown	18:35–20:00 (good, 1.42 h)	87.1° 14:00	11.4	4%	65.6°
2040-12-06 Thu	34	—	unknown	18:35–19:55 (good, 1.33 h)	87.1° 13:55	11.42	10%	66.2°
2040-12-07 Fri	31	—	unknown	18:35–19:45 (good, 1.17 h)	87.1° 13:50	11.43	18%	68.5°
2040-12-08 Sat	27	—	unknown	18:35–19:40 (good, 1.08 h)	87.1° 13:50	11.44	27%	72.2°
2040-12-09 Sun	23	—	unknown	18:35–19:30 (good, 0.92 h)	87.1° 13:45	11.45	38%	76.8°
2040-12-10 Mon	20	—	unknown	18:35–19:20 (good, 0.75 h)	87.1° 13:40	11.46	49%	82.1°
2040-12-11 Tue	18	—	unknown	18:35–19:15 (good, 0.67 h)	87.1° 13:35	11.47	60%	87.7°
2040-12-12 Wed	17	—	unknown	18:35–19:05 (good, 0.5 h)	87.1° 13:30	11.48	71%	93.2°
2040-12-13 Thu	16	—	unknown	18:35–19:00 (good, 0.42 h)	87.1° 13:30	11.48	80%	98.5°
2040-12-14 Fri	15	—	unknown	18:35–19:00 (good, 0.42 h)	87.1° 13:25	11.49	88%	103.4°
2040-12-15 Sat	15	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 13:20	11.49	94%	107.6°
2040-12-16 Sun	16	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 13:15	11.5	98%	110.9°
2040-12-17 Mon	16	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 13:15	11.5	100%	113.2°
2040-12-18 Tue	15	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 13:10	11.51	100%	114.3°
2040-12-19 Wed	15	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:05	11.51	98%	114.3°
2040-12-20 Thu	15	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:00	11.51	94%	113.1°
2040-12-21 Fri	16	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 12:55	11.51	89%	111.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2040-11-22&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.