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: 12-22 (100), 12-23 (100), 12-24 (100), 12-25 (100), 12-26 (100) — by astronomy; check the weather when the night is within four days.

2029-12-16astronomy score per night — click a bar for that night2030-01-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-12-16 Sun	28	—	unknown	18:35–01:45 (marginal, 7.17 h)	79.1° 20:15	11.5	86%	17.4°
2029-12-17 Mon	23	—	unknown	18:35–20:50 (marginal, 2.25 h)	79.1° 20:10	11.5	92%	25.3°
2029-12-18 Tue	25	—	unknown	18:35–21:30 (marginal, 2.92 h)	79.1° 20:05	11.5	96%	35.5°
2029-12-19 Wed	35	—	unknown	18:35–00:10 (marginal, 5.58 h)	79.1° 20:00	11.51	99%	46.6°
2029-12-20 Thu	52	—	unknown	18:00–01:15 (marginal, 7.25 h)	79.1° 20:00	11.51	100%	58.2°
2029-12-21 Fri	70	—	unknown	18:35–21:00 (good, 2.42 h)	79.1° 19:55	11.51	99%	70.1°
2029-12-22 Sat	100	—	unknown	18:35–23:05 (good, 4.5 h)	79.1° 19:50	11.51	96%	82.2°
2029-12-23 Sun	100	—	unknown	18:40–00:30 (good, 5.83 h)	79.1° 19:45	11.51	91%	94.6°
2029-12-24 Mon	100	—	unknown	18:40–00:55 (good, 6.25 h)	79.1° 19:40	11.5	84%	107.1°
2029-12-25 Tue	100	—	unknown	18:40–01:00 (good, 6.33 h)	79.1° 19:40	11.5	76%	119.7°
2029-12-26 Wed	100	—	unknown	18:40–01:00 (good, 6.33 h)	79.1° 19:35	11.49	66%	132.4°
2029-12-27 Thu	100	—	unknown	18:40–01:00 (good, 6.33 h)	79.1° 19:30	11.49	55%	145.0°
2029-12-28 Fri	100	—	unknown	18:40–01:00 (good, 6.33 h)	79.1° 19:25	11.48	44%	156.6°
2029-12-29 Sat	100	—	unknown	18:40–00:55 (good, 6.25 h)	79.1° 19:25	11.48	33%	164.4°
2029-12-30 Sun	100	—	unknown	18:40–00:50 (good, 6.17 h)	79.1° 19:20	11.47	23%	161.6°
2029-12-31 Mon	100	—	unknown	18:45–00:45 (good, 6.0 h)	79.1° 19:15	11.46	14%	150.9°
2030-01-01 Tue	100	—	unknown	18:45–00:45 (good, 6.0 h)	79.1° 19:10	11.45	6%	137.9°
2030-01-02 Wed	100	—	unknown	18:45–00:40 (good, 5.92 h)	79.1° 19:05	11.44	2%	124.2°
2030-01-03 Thu	100	—	unknown	18:45–00:35 (good, 5.83 h)	79.1° 19:05	11.43	0%	110.3°
2030-01-04 Fri	100	—	unknown	18:45–00:30 (good, 5.75 h)	79.1° 19:00	11.42	1%	96.5°
2030-01-05 Sat	100	—	unknown	18:45–00:30 (good, 5.75 h)	79.1° 18:55	11.4	4%	83.1°
2030-01-06 Sun	100	—	unknown	18:50–00:25 (good, 5.58 h)	79.1° 18:50	11.39	10%	70.0°
2030-01-07 Mon	100	—	unknown	18:50–00:20 (good, 5.5 h)	79.1° 18:45	11.37	17%	57.4°
2030-01-08 Tue	92	—	unknown	18:50–00:15 (good, 5.42 h)	79.1° 18:45	11.36	25%	45.4°
2030-01-09 Wed	83	—	unknown	18:50–00:10 (good, 5.33 h)	79.1° 18:40	11.34	34%	34.1°
2030-01-10 Thu	72	—	unknown	18:50–23:50 (good, 5.0 h)	79.1° 18:35	11.32	44%	24.0°
2030-01-11 Fri	56	—	unknown	18:50–22:35 (good, 3.75 h)	79.1° 18:30	11.3	53%	16.6°
2030-01-12 Sat	41	—	unknown	18:55–00:20 (marginal, 5.42 h)	79.1° 18:30	11.29	63%	16.0°
2030-01-13 Sun	29	—	unknown	18:55–00:05 (marginal, 5.17 h)	79.1° 18:25	11.27	71%	22.6°
2030-01-14 Mon	22	—	unknown	18:55–23:45 (marginal, 4.83 h)	79.1° 18:20	11.25	80%	32.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-12-16&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.