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: 09-04 (100), 09-05 (100), 09-06 (100), 09-07 (100), 09-08 (100) — by astronomy; check the weather when the night is within four days.

2030-09-04astronomy score per night — click a bar for that night2030-10-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-09-04 Wed	100	—	unknown	22:35–05:15 (good, 6.67 h)	79.1° 04:00	7.78	50%	136.7°
2030-09-05 Thu	100	—	unknown	22:35–05:15 (good, 6.67 h)	79.1° 03:55	7.83	62%	123.6°
2030-09-06 Fri	100	—	unknown	22:35–05:20 (good, 6.75 h)	79.1° 03:50	7.89	72%	110.2°
2030-09-07 Sat	100	—	unknown	22:40–05:20 (good, 6.67 h)	79.1° 03:50	7.94	82%	96.7°
2030-09-08 Sun	100	—	unknown	23:20–05:20 (good, 6.0 h)	79.1° 03:45	8.0	90%	83.3°
2030-09-09 Mon	100	—	unknown	01:05–05:25 (good, 4.33 h)	79.1° 03:40	8.05	95%	70.1°
2030-09-10 Tue	65	—	unknown	04:25–05:25 (good, 1.0 h)	79.1° 03:35	8.11	99%	57.2°
2030-09-11 Wed	43	—	unknown	22:10–05:25 (marginal, 7.25 h)	79.1° 03:30	8.16	100%	44.7°
2030-09-12 Thu	28	—	unknown	22:15–05:25 (marginal, 7.17 h)	79.1° 03:30	8.21	99%	33.1°
2030-09-13 Fri	24	—	unknown	22:00–02:00 (marginal, 4.0 h)	79.1° 03:25	8.27	95%	22.9°
2030-09-14 Sat	31	—	unknown	21:45–05:30 (marginal, 7.75 h)	79.1° 03:20	8.32	90%	16.7°
2030-09-15 Sun	41	—	unknown	21:30–05:30 (marginal, 8.0 h)	79.1° 03:15	8.37	84%	18.3°
2030-09-16 Mon	58	—	unknown	21:15–05:30 (marginal, 8.25 h)	79.1° 03:15	8.43	76%	26.0°
2030-09-17 Tue	82	—	unknown	21:40–01:40 (good, 4.0 h)	79.1° 03:10	8.48	68%	35.9°
2030-09-18 Wed	88	—	unknown	21:40–05:35 (good, 7.92 h)	79.1° 03:05	8.53	58%	46.6°
2030-09-19 Thu	94	—	unknown	21:35–05:35 (good, 8.0 h)	79.1° 03:00	8.58	49%	57.7°
2030-09-20 Fri	100	—	unknown	21:30–05:35 (good, 8.08 h)	79.1° 02:55	8.63	40%	69.0°
2030-09-21 Sat	100	—	unknown	21:25–05:35 (good, 8.17 h)	79.1° 02:55	8.69	30%	80.6°
2030-09-22 Sun	100	—	unknown	21:20–05:40 (good, 8.33 h)	79.1° 02:50	8.74	22%	92.5°
2030-09-23 Mon	100	—	unknown	21:20–05:40 (good, 8.33 h)	79.1° 02:45	8.79	14%	104.7°
2030-09-24 Tue	100	—	unknown	21:15–05:40 (good, 8.42 h)	79.1° 02:40	8.84	8%	117.1°
2030-09-25 Wed	100	—	unknown	21:10–05:40 (good, 8.5 h)	79.1° 02:35	8.89	3%	129.7°
2030-09-26 Thu	100	—	unknown	21:05–05:45 (good, 8.67 h)	79.1° 02:35	8.94	0%	142.3°
2030-09-27 Fri	100	—	unknown	21:00–05:45 (good, 8.75 h)	79.1° 02:30	8.99	0%	154.1°
2030-09-28 Sat	100	—	unknown	21:00–05:45 (good, 8.75 h)	79.1° 02:25	9.04	3%	162.6°
2030-09-29 Sun	100	—	unknown	20:55–05:45 (good, 8.83 h)	79.1° 02:20	9.08	8%	161.7°
2030-09-30 Mon	100	—	unknown	20:50–05:50 (good, 9.0 h)	79.1° 02:20	9.13	16%	152.2°
2030-10-01 Tue	100	—	unknown	20:50–05:50 (good, 9.0 h)	79.1° 02:15	9.18	25%	139.8°
2030-10-02 Wed	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.1° 02:10	9.23	36%	126.6°
2030-10-03 Thu	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.1° 02:05	9.28	47%	113.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-09-04&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.