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: 11-22 (100), 11-23 (100), 11-24 (100), 11-25 (100), 11-26 (100) — by astronomy; check the weather when the night is within four days.

2043-11-17astronomy score per night — click a bar for that night2043-12-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-11-17 Tue	26	—	unknown	19:25–21:55 (marginal, 2.5 h)	72.5° 00:25	11.01	98%	10.1°
2043-11-18 Wed	36	—	unknown	19:05–00:00 (marginal, 4.92 h)	72.6° 00:20	11.04	94%	25.3°
2043-11-19 Thu	63	—	unknown	19:10–19:15 (good, 0.08 h)	72.6° 00:15	11.07	87%	40.2°
2043-11-20 Fri	87	—	unknown	19:05–00:30 (good, 5.42 h)	72.6° 00:10	11.09	78%	54.8°
2043-11-21 Sat	97	—	unknown	19:00–03:35 (good, 8.58 h)	72.5° 00:05	11.12	68%	68.9°
2043-11-22 Sun	100	—	unknown	18:55–04:50 (good, 9.92 h)	72.5° 00:05	11.14	57%	82.6°
2043-11-23 Mon	100	—	unknown	18:55–04:55 (good, 10.0 h)	72.6° 00:00	11.16	46%	95.8°
2043-11-24 Tue	100	—	unknown	18:50–05:00 (good, 10.17 h)	72.6° 23:55	11.19	36%	108.7°
2043-11-25 Wed	100	—	unknown	18:45–05:00 (good, 10.25 h)	72.6° 23:50	11.21	27%	121.2°
2043-11-26 Thu	100	—	unknown	18:40–04:55 (good, 10.25 h)	72.5° 23:45	11.23	19%	133.5°
2043-11-27 Fri	100	—	unknown	18:35–04:55 (good, 10.33 h)	72.6° 23:45	11.25	12%	145.7°
2043-11-28 Sat	100	—	unknown	18:35–04:50 (good, 10.25 h)	72.6° 23:40	11.27	6%	157.6°
2043-11-29 Sun	100	—	unknown	18:35–04:45 (good, 10.17 h)	72.6° 23:35	11.29	3%	169.6°
2043-11-30 Mon	100	—	unknown	18:35–04:40 (good, 10.08 h)	72.6° 23:30	11.31	1%	178.6°
2043-12-01 Tue	100	—	unknown	18:35–04:40 (good, 10.08 h)	72.5° 23:30	11.33	0%	166.8°
2043-12-02 Wed	100	—	unknown	18:35–04:35 (good, 10.0 h)	72.6° 23:25	11.35	2%	154.9°
2043-12-03 Thu	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.6° 23:20	11.36	5%	143.1°
2043-12-04 Fri	100	—	unknown	18:35–04:25 (good, 9.83 h)	72.6° 23:15	11.38	10%	131.1°
2043-12-05 Sat	100	—	unknown	18:35–04:25 (good, 9.83 h)	72.6° 23:10	11.39	16%	119.1°
2043-12-06 Sun	100	—	unknown	18:35–04:20 (good, 9.75 h)	72.5° 23:10	11.41	24%	106.9°
2043-12-07 Mon	100	—	unknown	18:35–04:15 (good, 9.67 h)	72.6° 23:05	11.42	33%	94.5°
2043-12-08 Tue	100	—	unknown	18:35–04:10 (good, 9.58 h)	72.6° 23:00	11.43	42%	81.8°
2043-12-09 Wed	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.6° 22:55	11.44	53%	68.7°
2043-12-10 Thu	95	—	unknown	19:45–04:05 (good, 8.33 h)	72.5° 22:50	11.45	64%	55.3°
2043-12-11 Fri	86	—	unknown	23:50–04:00 (good, 4.17 h)	72.6° 22:50	11.46	74%	41.4°
2043-12-12 Sat	55	—	unknown	18:35–04:25 (marginal, 9.83 h)	72.6° 22:45	11.47	83%	27.0°
2043-12-13 Sun	35	—	unknown	22:25–04:00 (marginal, 5.58 h)	72.6° 22:40	11.48	91%	12.2°
2043-12-14 Mon	22	—	unknown	02:20–03:30 (marginal, 1.17 h)	72.6° 22:35	11.49	97%	2.9°
2043-12-15 Tue	23	—	unknown	18:35–20:35 (marginal, 2.0 h)	72.5° 22:30	11.49	100%	18.2°
2043-12-16 Wed	31	—	unknown	18:35–22:15 (marginal, 3.67 h)	72.6° 22:30	11.5	99%	33.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-11-17&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.