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: 12-11 (100), 12-12 (100), 12-24 (100), 12-25 (100), 12-26 (100) — by astronomy; check the weather when the night is within four days.

2037-12-11astronomy score per night — click a bar for that night2038-01-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-12-11 Fri	100	—	unknown	18:35–02:05 (good, 7.5 h)	79.2° 20:35	11.47	25%	74.7°
2037-12-12 Sat	100	—	unknown	18:35–02:00 (good, 7.42 h)	79.2° 20:30	11.47	34%	63.7°
2037-12-13 Sun	96	—	unknown	18:35–02:00 (good, 7.42 h)	79.2° 20:25	11.48	44%	53.2°
2037-12-14 Mon	88	—	unknown	18:35–01:55 (good, 7.33 h)	79.2° 20:20	11.49	53%	43.3°
2037-12-15 Tue	81	—	unknown	20:35–01:50 (good, 5.25 h)	79.2° 20:20	11.49	62%	34.5°
2037-12-16 Wed	54	—	unknown	18:35–02:10 (marginal, 7.58 h)	79.2° 20:15	11.5	71%	27.6°
2037-12-17 Thu	39	—	unknown	18:35–02:00 (marginal, 7.42 h)	79.2° 20:10	11.5	79%	24.5°
2037-12-18 Fri	30	—	unknown	18:35–01:35 (marginal, 7.0 h)	79.2° 20:05	11.5	87%	26.6°
2037-12-19 Sat	27	—	unknown	18:35–01:10 (marginal, 6.58 h)	79.2° 20:00	11.51	93%	33.2°
2037-12-20 Sun	33	—	unknown	18:35–00:40 (marginal, 6.08 h)	79.2° 20:00	11.51	97%	42.5°
2037-12-21 Mon	44	—	unknown	18:35–01:05 (marginal, 6.5 h)	79.2° 19:55	11.51	100%	53.2°
2037-12-22 Tue	61	—	unknown	18:35–19:45 (good, 1.17 h)	79.2° 19:50	11.51	100%	64.7°
2037-12-23 Wed	75	—	unknown	18:40–22:20 (good, 3.67 h)	79.2° 19:45	11.5	98%	76.9°
2037-12-24 Thu	100	—	unknown	18:40–23:50 (good, 5.17 h)	79.2° 19:45	11.5	94%	89.3°
2037-12-25 Fri	100	—	unknown	18:40–00:45 (good, 6.08 h)	79.2° 19:40	11.5	87%	101.9°
2037-12-26 Sat	100	—	unknown	18:40–00:55 (good, 6.25 h)	79.2° 19:35	11.49	78%	114.5°
2037-12-27 Sun	100	—	unknown	18:40–00:55 (good, 6.25 h)	79.2° 19:30	11.49	68%	126.8°
2037-12-28 Mon	100	—	unknown	18:40–00:55 (good, 6.25 h)	79.2° 19:25	11.48	57%	138.4°
2037-12-29 Tue	100	—	unknown	18:40–00:55 (good, 6.25 h)	79.2° 19:25	11.48	46%	148.4°
2037-12-30 Wed	100	—	unknown	18:40–00:50 (good, 6.17 h)	79.2° 19:20	11.47	35%	154.7°
2037-12-31 Thu	100	—	unknown	18:45–00:50 (good, 6.08 h)	79.2° 19:15	11.46	24%	154.4°
2038-01-01 Fri	100	—	unknown	18:45–00:45 (good, 6.0 h)	79.2° 19:10	11.45	15%	147.8°
2038-01-02 Sat	100	—	unknown	18:45–00:40 (good, 5.92 h)	79.2° 19:05	11.44	8%	137.7°
2038-01-03 Sun	100	—	unknown	18:45–00:35 (good, 5.83 h)	79.2° 19:05	11.43	3%	126.3°
2038-01-04 Mon	100	—	unknown	18:45–00:30 (good, 5.75 h)	79.2° 19:00	11.41	0%	114.4°
2038-01-05 Tue	100	—	unknown	18:45–00:30 (good, 5.75 h)	79.2° 18:55	11.4	0%	102.4°
2038-01-06 Wed	100	—	unknown	18:50–00:25 (good, 5.58 h)	79.2° 18:50	11.39	2%	90.5°
2038-01-07 Thu	100	—	unknown	18:50–00:20 (good, 5.5 h)	79.2° 18:50	11.37	6%	78.9°
2038-01-08 Fri	100	—	unknown	18:50–00:15 (good, 5.42 h)	79.2° 18:45	11.36	12%	67.6°
2038-01-09 Sat	99	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:40	11.34	18%	56.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-12-11&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.