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: 11-27 (100), 11-28 (100), 11-29 (100), 11-30 (100), 12-01 (100) — by astronomy; check the weather when the night is within four days.

2026-11-21astronomy score per night — click a bar for that night2026-12-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2026-11-21 Sat	38	—	unknown	18:35–03:35 (marginal, 9.0 h)	79.1° 21:55	11.12	90%	18.2°
2026-11-22 Sun	26	—	unknown	00:45–03:10 (marginal, 2.42 h)	79.1° 21:50	11.14	96%	15.1°
2026-11-23 Mon	24	—	unknown	18:35–20:30 (marginal, 1.92 h)	79.1° 21:45	11.17	99%	23.1°
2026-11-24 Tue	33	—	unknown	18:35–22:05 (marginal, 3.5 h)	79.1° 21:40	11.19	100%	35.8°
2026-11-25 Wed	58	—	unknown	18:35–02:40 (marginal, 8.08 h)	79.1° 21:35	11.21	97%	49.7°
2026-11-26 Thu	71	—	unknown	18:35–22:00 (good, 3.42 h)	79.1° 21:35	11.23	92%	64.1°
2026-11-27 Fri	100	—	unknown	18:35–01:00 (good, 6.42 h)	79.1° 21:30	11.26	84%	78.4°
2026-11-28 Sat	100	—	unknown	18:35–02:30 (good, 7.92 h)	79.1° 21:25	11.28	75%	92.6°
2026-11-29 Sun	100	—	unknown	18:35–02:40 (good, 8.08 h)	79.1° 21:20	11.3	65%	106.4°
2026-11-30 Mon	100	—	unknown	18:35–02:45 (good, 8.17 h)	79.1° 21:20	11.31	54%	119.7°
2026-12-01 Tue	100	—	unknown	18:35–02:40 (good, 8.08 h)	79.1° 21:15	11.33	43%	132.5°
2026-12-02 Wed	100	—	unknown	18:35–02:40 (good, 8.08 h)	79.1° 21:10	11.35	33%	144.7°
2026-12-03 Thu	100	—	unknown	18:35–02:40 (good, 8.08 h)	79.1° 21:05	11.36	23%	155.7°
2026-12-04 Fri	100	—	unknown	18:35–02:35 (good, 8.0 h)	79.1° 21:00	11.38	16%	163.8°
2026-12-05 Sat	100	—	unknown	18:35–02:30 (good, 7.92 h)	79.1° 21:00	11.39	9%	164.4°
2026-12-06 Sun	100	—	unknown	18:35–02:25 (good, 7.83 h)	79.1° 20:55	11.41	4%	157.2°
2026-12-07 Mon	100	—	unknown	18:35–02:20 (good, 7.75 h)	79.1° 20:50	11.42	1%	147.1°
2026-12-08 Tue	100	—	unknown	18:35–02:20 (good, 7.75 h)	79.1° 20:45	11.43	0%	136.2°
2026-12-09 Wed	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.1° 20:40	11.44	1%	124.9°
2026-12-10 Thu	100	—	unknown	18:35–02:10 (good, 7.58 h)	79.1° 20:40	11.45	3%	113.6°
2026-12-11 Fri	100	—	unknown	18:35–02:05 (good, 7.5 h)	79.1° 20:35	11.46	7%	102.2°
2026-12-12 Sat	100	—	unknown	18:35–02:05 (good, 7.5 h)	79.1° 20:30	11.47	13%	90.8°
2026-12-13 Sun	100	—	unknown	18:35–02:00 (good, 7.42 h)	79.1° 20:25	11.48	20%	79.3°
2026-12-14 Mon	100	—	unknown	18:35–01:55 (good, 7.33 h)	79.1° 20:25	11.49	28%	67.7°
2026-12-15 Tue	99	—	unknown	18:35–01:50 (good, 7.25 h)	79.1° 20:20	11.49	37%	56.0°
2026-12-16 Wed	90	—	unknown	18:35–01:45 (good, 7.17 h)	79.1° 20:15	11.5	47%	44.3°
2026-12-17 Thu	82	—	unknown	18:35–01:45 (good, 7.17 h)	79.1° 20:10	11.5	57%	32.6°
2026-12-18 Fri	56	—	unknown	18:35–02:05 (marginal, 7.5 h)	79.1° 20:05	11.5	67%	21.7°
2026-12-19 Sat	38	—	unknown	18:35–01:50 (marginal, 7.25 h)	79.1° 20:05	11.51	77%	14.7°
2026-12-20 Sun	26	—	unknown	18:35–01:25 (marginal, 6.83 h)	79.1° 20:00	11.51	86%	18.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-11-21&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.