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: 09-14 (100), 09-15 (100), 09-16 (100), 09-17 (100), 09-18 (100) — by astronomy; check the weather when the night is within four days.

2047-09-10astronomy score per night — click a bar for that night2047-10-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-09-10 Tue	69	—	unknown	23:10–01:50 (good, 2.67 h)	79.2° 03:40	8.1	64%	31.7°
2047-09-11 Wed	84	—	unknown	22:05–05:25 (good, 7.33 h)	79.2° 03:35	8.16	55%	42.5°
2047-09-12 Thu	91	—	unknown	22:00–05:25 (good, 7.42 h)	79.2° 03:30	8.21	46%	53.8°
2047-09-13 Fri	98	—	unknown	22:00–05:30 (good, 7.5 h)	79.2° 03:25	8.26	36%	65.5°
2047-09-14 Sat	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.2° 03:20	8.32	27%	77.7°
2047-09-15 Sun	100	—	unknown	21:50–05:30 (good, 7.67 h)	79.2° 03:20	8.37	18%	90.3°
2047-09-16 Mon	100	—	unknown	21:45–05:30 (good, 7.75 h)	79.2° 03:15	8.42	10%	103.2°
2047-09-17 Tue	100	—	unknown	21:45–05:30 (good, 7.75 h)	79.2° 03:10	8.47	5%	116.6°
2047-09-18 Wed	100	—	unknown	21:40–05:35 (good, 7.92 h)	79.2° 03:05	8.52	1%	130.2°
2047-09-19 Thu	100	—	unknown	21:35–05:35 (good, 8.0 h)	79.2° 03:00	8.58	0%	143.7°
2047-09-20 Fri	100	—	unknown	21:30–05:35 (good, 8.08 h)	79.2° 03:00	8.63	2%	156.3°
2047-09-21 Sat	100	—	unknown	21:25–05:35 (good, 8.17 h)	79.2° 02:55	8.68	7%	164.8°
2047-09-22 Sun	100	—	unknown	21:25–05:40 (good, 8.25 h)	79.2° 02:50	8.73	14%	161.8°
2047-09-23 Mon	100	—	unknown	21:20–05:40 (good, 8.33 h)	79.2° 02:45	8.78	23%	150.8°
2047-09-24 Tue	100	—	unknown	21:20–05:40 (good, 8.33 h)	79.2° 02:45	8.83	34%	137.9°
2047-09-25 Wed	100	—	unknown	21:15–05:40 (good, 8.42 h)	79.2° 02:40	8.88	45%	124.6°
2047-09-26 Thu	100	—	unknown	21:15–05:45 (good, 8.5 h)	79.2° 02:35	8.93	56%	111.4°
2047-09-27 Fri	100	—	unknown	21:20–05:45 (good, 8.42 h)	79.2° 02:30	8.98	66%	98.4°
2047-09-28 Sat	100	—	unknown	21:25–05:45 (good, 8.33 h)	79.2° 02:25	9.03	76%	85.7°
2047-09-29 Sun	100	—	unknown	22:35–05:45 (good, 7.17 h)	79.2° 02:25	9.08	84%	73.2°
2047-09-30 Mon	100	—	unknown	01:20–05:50 (good, 4.5 h)	79.2° 02:20	9.13	91%	60.9°
2047-10-01 Tue	92	—	unknown	04:15–05:50 (good, 1.58 h)	79.2° 02:15	9.18	96%	49.0°
2047-10-02 Wed	49	—	unknown	20:55–05:50 (marginal, 8.92 h)	79.2° 02:10	9.22	99%	37.6°
2047-10-03 Thu	32	—	unknown	02:50–05:50 (marginal, 3.0 h)	79.2° 02:05	9.27	100%	26.9°
2047-10-04 Fri	27	—	unknown	20:40–23:30 (marginal, 2.83 h)	79.2° 02:05	9.32	99%	18.1°
2047-10-05 Sat	31	—	unknown	20:30–00:30 (marginal, 4.0 h)	79.2° 02:00	9.37	96%	14.8°
2047-10-06 Sun	39	—	unknown	20:30–02:00 (marginal, 5.5 h)	79.2° 01:55	9.41	92%	19.6°
2047-10-07 Mon	50	—	unknown	20:30–05:55 (marginal, 9.42 h)	79.2° 01:50	9.46	86%	28.7°
2047-10-08 Tue	82	—	unknown	20:25–21:05 (good, 0.67 h)	79.2° 01:50	9.5	79%	39.2°
2047-10-09 Wed	88	—	unknown	20:25–02:15 (good, 5.83 h)	79.2° 01:45	9.55	71%	50.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-09-10&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.