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 Seven Sisters: 11-20 (100), 11-21 (100), 11-22 (100), 11-23 (100), 11-24 (100) — by astronomy; check the weather when the night is within four days.

2035-11-16astronomy score per night — click a bar for that night2035-12-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-11-16 Fri	34	—	unknown	19:15–23:20 (marginal, 4.08 h)	72.5° 00:25	10.98	97%	16.0°
2035-11-17 Sat	52	—	unknown	18:50–01:35 (marginal, 6.75 h)	72.5° 00:20	11.01	92%	29.4°
2035-11-18 Sun	83	—	unknown	19:15–20:10 (good, 0.92 h)	72.5° 00:20	11.04	84%	43.6°
2035-11-19 Mon	92	—	unknown	19:10–02:05 (good, 6.92 h)	72.5° 00:15	11.06	75%	57.9°
2035-11-20 Tue	100	—	unknown	19:05–04:10 (good, 9.08 h)	72.5° 00:10	11.09	64%	72.0°
2035-11-21 Wed	100	—	unknown	19:00–05:00 (good, 10.0 h)	72.5° 00:05	11.11	53%	85.9°
2035-11-22 Thu	100	—	unknown	18:55–05:05 (good, 10.17 h)	72.5° 00:05	11.14	42%	99.5°
2035-11-23 Fri	100	—	unknown	18:55–05:05 (good, 10.17 h)	72.5° 00:00	11.16	32%	112.7°
2035-11-24 Sat	100	—	unknown	18:50–05:05 (good, 10.25 h)	72.5° 23:55	11.19	22%	125.6°
2035-11-25 Sun	100	—	unknown	18:45–05:00 (good, 10.25 h)	72.5° 23:50	11.21	15%	138.3°
2035-11-26 Mon	100	—	unknown	18:40–04:55 (good, 10.25 h)	72.5° 23:45	11.23	8%	150.5°
2035-11-27 Tue	100	—	unknown	18:35–04:55 (good, 10.33 h)	72.5° 23:45	11.25	4%	161.9°
2035-11-28 Wed	100	—	unknown	18:35–04:50 (good, 10.25 h)	72.5° 23:40	11.27	1%	170.3°
2035-11-29 Thu	100	—	unknown	18:35–04:45 (good, 10.17 h)	72.5° 23:35	11.29	0%	167.3°
2035-11-30 Fri	100	—	unknown	18:35–04:40 (good, 10.08 h)	72.5° 23:30	11.31	1%	157.2°
2035-12-01 Sat	100	—	unknown	18:35–04:40 (good, 10.08 h)	72.5° 23:25	11.33	4%	146.0°
2035-12-02 Sun	100	—	unknown	18:35–04:35 (good, 10.0 h)	72.5° 23:25	11.34	9%	134.5°
2035-12-03 Mon	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.5° 23:20	11.36	15%	123.0°
2035-12-04 Tue	100	—	unknown	18:35–04:25 (good, 9.83 h)	72.5° 23:15	11.38	22%	111.3°
2035-12-05 Wed	100	—	unknown	18:35–04:20 (good, 9.75 h)	72.5° 23:10	11.39	30%	99.6°
2035-12-06 Thu	100	—	unknown	18:35–04:20 (good, 9.75 h)	72.5° 23:10	11.4	39%	87.7°
2035-12-07 Fri	100	—	unknown	18:35–04:15 (good, 9.67 h)	72.5° 23:05	11.42	49%	75.7°
2035-12-08 Sat	100	—	unknown	18:45–04:10 (good, 9.42 h)	72.5° 23:00	11.43	59%	63.3°
2035-12-09 Sun	93	—	unknown	20:40–04:05 (good, 7.42 h)	72.5° 22:55	11.44	69%	50.6°
2035-12-10 Mon	84	—	unknown	01:15–02:55 (good, 1.67 h)	72.5° 22:50	11.45	78%	37.5°
2035-12-11 Tue	54	—	unknown	18:35–04:25 (marginal, 9.83 h)	72.5° 22:50	11.46	87%	24.4°
2035-12-12 Wed	34	—	unknown	18:35–04:00 (marginal, 9.42 h)	72.5° 22:45	11.47	93%	12.3°
2035-12-13 Thu	27	—	unknown	18:35–21:00 (marginal, 2.42 h)	72.5° 22:40	11.48	98%	11.2°
2035-12-14 Fri	29	—	unknown	18:35–21:30 (marginal, 2.92 h)	72.5° 22:35	11.48	100%	23.3°
2035-12-15 Sat	44	—	unknown	18:35–00:25 (marginal, 5.83 h)	72.5° 22:30	11.49	99%	37.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-11-16&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.