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: 12-30 (100), 12-31 (100), 01-01 (100), 01-02 (100), 01-03 (100) — by astronomy; check the weather when the night is within four days.

2031-12-20astronomy score per night — click a bar for that night2032-01-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-12-20 Sat	86	—	unknown	18:35–01:30 (good, 6.92 h)	79.1° 20:00	11.51	49%	37.7°
2031-12-21 Sun	63	—	unknown	21:20–00:40 (good, 3.33 h)	79.1° 19:55	11.51	60%	26.8°
2031-12-22 Mon	49	—	unknown	18:35–01:50 (marginal, 7.25 h)	79.1° 19:50	11.51	70%	19.2°
2031-12-23 Tue	33	—	unknown	18:40–01:30 (marginal, 6.83 h)	79.1° 19:50	11.51	79%	18.9°
2031-12-24 Wed	25	—	unknown	18:40–01:05 (marginal, 6.42 h)	79.1° 19:45	11.5	87%	25.7°
2031-12-25 Thu	25	—	unknown	18:40–00:00 (marginal, 5.33 h)	79.1° 19:40	11.5	93%	35.5°
2031-12-26 Fri	33	—	unknown	18:40–00:45 (marginal, 6.08 h)	79.1° 19:35	11.5	97%	46.3°
2031-12-27 Sat	45	—	unknown	18:40–00:50 (marginal, 6.17 h)	79.1° 19:35	11.49	99%	57.6°
2031-12-28 Sun	62	—	unknown	18:40–20:15 (good, 1.58 h)	79.1° 19:30	11.49	100%	68.9°
2031-12-29 Mon	76	—	unknown	18:40–22:20 (good, 3.67 h)	79.1° 19:25	11.48	98%	80.2°
2031-12-30 Tue	100	—	unknown	18:40–23:35 (good, 4.92 h)	79.1° 19:20	11.47	96%	91.5°
2031-12-31 Wed	100	—	unknown	18:45–00:25 (good, 5.67 h)	79.1° 19:15	11.46	91%	102.7°
2032-01-01 Thu	100	—	unknown	18:45–00:30 (good, 5.75 h)	79.1° 19:15	11.45	85%	113.9°
2032-01-02 Fri	100	—	unknown	18:45–00:35 (good, 5.83 h)	79.1° 19:10	11.44	77%	125.0°
2032-01-03 Sat	100	—	unknown	18:45–00:30 (good, 5.75 h)	79.1° 19:05	11.43	69%	135.9°
2032-01-04 Sun	100	—	unknown	18:45–00:30 (good, 5.75 h)	79.1° 19:00	11.42	60%	146.4°
2032-01-05 Mon	100	—	unknown	18:45–00:30 (good, 5.75 h)	79.1° 18:55	11.41	50%	155.8°
2032-01-06 Tue	100	—	unknown	18:45–00:25 (good, 5.67 h)	79.1° 18:55	11.39	40%	161.6°
2032-01-07 Wed	100	—	unknown	18:50–00:20 (good, 5.5 h)	79.1° 18:50	11.38	30%	159.6°
2032-01-08 Thu	100	—	unknown	18:50–00:20 (good, 5.5 h)	79.1° 18:45	11.36	20%	150.9°
2032-01-09 Fri	100	—	unknown	18:50–00:15 (good, 5.42 h)	79.1° 18:40	11.35	12%	139.0°
2032-01-10 Sat	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.1° 18:40	11.33	5%	125.8°
2032-01-11 Sun	100	—	unknown	18:50–00:05 (good, 5.25 h)	79.1° 18:35	11.31	1%	111.8°
2032-01-12 Mon	100	—	unknown	18:55–00:00 (good, 5.08 h)	79.1° 18:30	11.3	0%	97.4°
2032-01-13 Tue	100	—	unknown	18:55–00:00 (good, 5.08 h)	79.1° 18:25	11.28	2%	82.9°
2032-01-14 Wed	100	—	unknown	18:55–23:55 (good, 5.0 h)	79.1° 18:20	11.26	7%	68.6°
2032-01-15 Thu	98	—	unknown	18:55–23:50 (good, 4.92 h)	79.1° 18:20	11.23	14%	54.7°
2032-01-16 Fri	89	—	unknown	18:55–23:45 (good, 4.83 h)	79.1° 18:15	11.21	23%	41.5°
2032-01-17 Sat	80	—	unknown	19:00–23:40 (good, 4.67 h)	79.1° 18:10	11.19	33%	29.7°
2032-01-18 Sun	63	—	unknown	19:00–23:15 (good, 4.25 h)	79.1° 18:05	11.17	44%	20.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-12-20&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.