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 Triangulum Pinwheel: 11-20 (100), 11-21 (100), 11-22 (100), 12-03 (100), 12-04 (100) — by astronomy; check the weather when the night is within four days.

2039-11-20astronomy score per night — click a bar for that night2039-12-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-11-20 Sun	100	—	unknown	18:35–03:30 (good, 8.92 h)	79.2° 22:00	11.09	29%	91.5°
2039-11-21 Mon	100	—	unknown	18:35–03:25 (good, 8.83 h)	79.2° 21:55	11.12	39%	78.5°
2039-11-22 Tue	100	—	unknown	18:35–03:25 (good, 8.83 h)	79.2° 21:50	11.14	50%	66.0°
2039-11-23 Wed	96	—	unknown	18:35–03:20 (good, 8.75 h)	79.2° 21:45	11.16	61%	54.1°
2039-11-24 Thu	87	—	unknown	21:40–03:15 (good, 5.58 h)	79.2° 21:45	11.19	71%	43.0°
2039-11-25 Fri	73	—	unknown	02:50–03:10 (good, 0.33 h)	79.2° 21:40	11.21	80%	33.2°
2039-11-26 Sat	44	—	unknown	18:35–03:25 (marginal, 8.83 h)	79.2° 21:35	11.23	87%	25.7°
2039-11-27 Sun	32	—	unknown	18:35–03:05 (marginal, 8.5 h)	79.2° 21:30	11.25	93%	22.7°
2039-11-28 Mon	28	—	unknown	18:35–21:00 (marginal, 2.42 h)	79.2° 21:25	11.27	97%	25.6°
2039-11-29 Tue	30	—	unknown	18:35–21:25 (marginal, 2.83 h)	79.2° 21:25	11.29	99%	32.7°
2039-11-30 Wed	41	—	unknown	18:35–00:00 (marginal, 5.42 h)	79.2° 21:20	11.31	100%	41.8°
2039-12-01 Thu	59	—	unknown	18:35–19:00 (good, 0.42 h)	79.2° 21:15	11.33	99%	51.9°
2039-12-02 Fri	70	—	unknown	18:35–21:00 (good, 2.42 h)	79.2° 21:10	11.35	96%	62.4°
2039-12-03 Sat	100	—	unknown	18:35–23:40 (good, 5.08 h)	79.2° 21:05	11.36	91%	73.1°
2039-12-04 Sun	100	—	unknown	18:35–01:05 (good, 6.5 h)	79.2° 21:05	11.38	85%	84.1°
2039-12-05 Mon	100	—	unknown	18:35–02:05 (good, 7.5 h)	79.2° 21:00	11.39	77%	95.1°
2039-12-06 Tue	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.2° 20:55	11.41	69%	106.2°
2039-12-07 Wed	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.2° 20:50	11.42	59%	117.4°
2039-12-08 Thu	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.2° 20:50	11.43	49%	128.6°
2039-12-09 Fri	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.2° 20:45	11.44	39%	139.5°
2039-12-10 Sat	100	—	unknown	18:35–02:10 (good, 7.58 h)	79.2° 20:40	11.45	29%	149.4°
2039-12-11 Sun	100	—	unknown	18:35–02:10 (good, 7.58 h)	79.2° 20:35	11.46	19%	156.2°
2039-12-12 Mon	100	—	unknown	18:35–02:05 (good, 7.5 h)	79.2° 20:30	11.47	11%	156.2°
2039-12-13 Tue	100	—	unknown	18:35–02:00 (good, 7.42 h)	79.2° 20:30	11.48	5%	148.8°
2039-12-14 Wed	100	—	unknown	18:35–01:55 (good, 7.33 h)	79.2° 20:25	11.48	1%	137.4°
2039-12-15 Thu	100	—	unknown	18:35–01:50 (good, 7.25 h)	79.2° 20:20	11.49	0%	124.2°
2039-12-16 Fri	100	—	unknown	18:35–01:50 (good, 7.25 h)	79.2° 20:15	11.5	2%	110.5°
2039-12-17 Sat	100	—	unknown	18:35–01:45 (good, 7.17 h)	79.2° 20:10	11.5	8%	96.7°
2039-12-18 Sun	100	—	unknown	18:35–01:40 (good, 7.08 h)	79.2° 20:10	11.5	15%	83.1°
2039-12-19 Mon	100	—	unknown	18:35–01:35 (good, 7.0 h)	79.2° 20:05	11.51	24%	69.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-11-20&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.