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: 11-22 (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.

2040-11-19astronomy score per night — click a bar for that night2040-12-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2040-11-19 Mon	47	—	unknown	18:35–00:45 (marginal, 6.17 h)	79.2° 22:00	11.08	99%	41.3°
2040-11-20 Tue	62	—	unknown	18:35–19:55 (good, 1.33 h)	79.2° 21:55	11.11	95%	52.1°
2040-11-21 Wed	95	—	unknown	18:35–22:20 (good, 3.75 h)	79.2° 21:50	11.13	90%	63.2°
2040-11-22 Thu	100	—	unknown	18:35–00:55 (good, 6.33 h)	79.2° 21:50	11.16	84%	74.3°
2040-11-23 Fri	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.2° 21:45	11.18	76%	85.4°
2040-11-24 Sat	100	—	unknown	18:35–02:50 (good, 8.25 h)	79.2° 21:40	11.2	68%	96.4°
2040-11-25 Sun	100	—	unknown	18:35–02:55 (good, 8.33 h)	79.2° 21:35	11.23	59%	107.4°
2040-11-26 Mon	100	—	unknown	18:35–03:00 (good, 8.42 h)	79.2° 21:30	11.25	50%	118.4°
2040-11-27 Tue	100	—	unknown	18:35–02:55 (good, 8.33 h)	79.2° 21:30	11.27	40%	129.2°
2040-11-28 Wed	100	—	unknown	18:35–02:55 (good, 8.33 h)	79.2° 21:25	11.29	31%	139.8°
2040-11-29 Thu	100	—	unknown	18:35–02:50 (good, 8.25 h)	79.2° 21:20	11.31	22%	149.5°
2040-11-30 Fri	100	—	unknown	18:35–02:50 (good, 8.25 h)	79.2° 21:15	11.32	14%	156.9°
2040-12-01 Sat	100	—	unknown	18:35–02:45 (good, 8.17 h)	79.2° 21:10	11.34	7%	158.4°
2040-12-02 Sun	100	—	unknown	18:35–02:40 (good, 8.08 h)	79.2° 21:10	11.36	2%	152.5°
2040-12-03 Mon	100	—	unknown	18:35–02:35 (good, 8.0 h)	79.2° 21:05	11.37	0%	142.1°
2040-12-04 Tue	100	—	unknown	18:35–02:35 (good, 8.0 h)	79.2° 21:00	11.39	1%	129.8°
2040-12-05 Wed	100	—	unknown	18:35–02:30 (good, 7.92 h)	79.2° 20:55	11.4	4%	116.5°
2040-12-06 Thu	100	—	unknown	18:35–02:25 (good, 7.83 h)	79.2° 20:55	11.42	10%	102.9°
2040-12-07 Fri	100	—	unknown	18:35–02:20 (good, 7.75 h)	79.2° 20:50	11.43	18%	89.3°
2040-12-08 Sat	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.2° 20:45	11.44	27%	75.7°
2040-12-09 Sun	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.2° 20:40	11.45	38%	62.6°
2040-12-10 Mon	93	—	unknown	18:35–02:10 (good, 7.58 h)	79.2° 20:35	11.46	49%	49.9°
2040-12-11 Tue	84	—	unknown	18:35–02:05 (good, 7.5 h)	79.2° 20:35	11.47	60%	38.2°
2040-12-12 Wed	56	—	unknown	18:35–02:30 (marginal, 7.92 h)	79.2° 20:30	11.48	71%	28.2°
2040-12-13 Thu	40	—	unknown	18:35–02:15 (marginal, 7.67 h)	79.2° 20:25	11.48	80%	21.9°
2040-12-14 Fri	29	—	unknown	18:35–01:50 (marginal, 7.25 h)	79.2° 20:20	11.49	88%	22.3°
2040-12-15 Sat	23	—	unknown	18:35–20:45 (marginal, 2.17 h)	79.2° 20:15	11.49	94%	28.8°
2040-12-16 Sun	28	—	unknown	18:35–22:25 (marginal, 3.83 h)	79.2° 20:15	11.5	98%	38.3°
2040-12-17 Mon	39	—	unknown	18:35–00:35 (marginal, 6.0 h)	79.2° 20:10	11.5	100%	48.8°
2040-12-18 Tue	55	—	unknown	18:35–19:00 (good, 0.42 h)	79.2° 20:05	11.51	100%	59.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2040-11-19&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.