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.

2035-09-04astronomy score per night — click a bar for that night2035-10-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-09-04 Tue	100	—	unknown	22:35–05:15 (good, 6.67 h)	79.1° 04:00	7.77	10%	152.8°
2035-09-05 Wed	100	—	unknown	22:30–05:15 (good, 6.75 h)	79.1° 03:55	7.82	17%	156.2°
2035-09-06 Thu	100	—	unknown	22:25–05:20 (good, 6.92 h)	79.1° 03:55	7.88	25%	153.5°
2035-09-07 Fri	100	—	unknown	22:25–05:20 (good, 6.92 h)	79.1° 03:50	7.93	34%	146.5°
2035-09-08 Sat	100	—	unknown	22:20–05:20 (good, 7.0 h)	79.1° 03:45	7.99	43%	137.4°
2035-09-09 Sun	100	—	unknown	22:20–05:20 (good, 7.0 h)	79.1° 03:40	8.04	53%	127.5°
2035-09-10 Mon	100	—	unknown	22:15–05:25 (good, 7.17 h)	79.1° 03:35	8.1	62%	117.1°
2035-09-11 Tue	100	—	unknown	22:20–05:25 (good, 7.08 h)	79.1° 03:35	8.15	71%	106.4°
2035-09-12 Wed	100	—	unknown	22:25–05:25 (good, 7.0 h)	79.1° 03:30	8.2	80%	95.5°
2035-09-13 Thu	100	—	unknown	22:45–05:25 (good, 6.67 h)	79.1° 03:25	8.26	87%	84.5°
2035-09-14 Fri	100	—	unknown	00:05–05:30 (good, 5.42 h)	79.1° 03:20	8.31	93%	73.3°
2035-09-15 Sat	72	—	unknown	02:45–05:30 (good, 2.75 h)	79.1° 03:20	8.36	97%	62.0°
2035-09-16 Sun	61	—	unknown	05:15–05:30 (good, 0.25 h)	79.1° 03:15	8.42	100%	50.8°
2035-09-17 Mon	42	—	unknown	21:40–05:30 (marginal, 7.83 h)	79.1° 03:10	8.47	100%	40.0°
2035-09-18 Tue	30	—	unknown	21:35–05:35 (marginal, 8.0 h)	79.1° 03:05	8.52	98%	30.6°
2035-09-19 Wed	34	—	unknown	21:20–05:35 (marginal, 8.25 h)	79.1° 03:00	8.57	94%	24.5°
2035-09-20 Thu	47	—	unknown	21:00–05:35 (marginal, 8.58 h)	79.1° 03:00	8.62	87%	24.8°
2035-09-21 Fri	80	—	unknown	21:25–22:00 (good, 0.58 h)	79.1° 02:55	8.67	79%	31.5°
2035-09-22 Sat	86	—	unknown	21:25–02:20 (good, 4.92 h)	79.1° 02:50	8.73	69%	41.7°
2035-09-23 Sun	92	—	unknown	21:20–05:40 (good, 8.33 h)	79.1° 02:45	8.78	58%	53.5°
2035-09-24 Mon	100	—	unknown	21:15–05:40 (good, 8.42 h)	79.1° 02:40	8.83	46%	66.0°
2035-09-25 Tue	100	—	unknown	21:10–05:40 (good, 8.5 h)	79.1° 02:40	8.88	35%	78.9°
2035-09-26 Wed	100	—	unknown	21:05–05:45 (good, 8.67 h)	79.1° 02:35	8.93	25%	91.8°
2035-09-27 Thu	100	—	unknown	21:05–05:45 (good, 8.67 h)	79.1° 02:30	8.98	16%	104.7°
2035-09-28 Fri	100	—	unknown	21:00–05:45 (good, 8.75 h)	79.1° 02:25	9.02	8%	117.4°
2035-09-29 Sat	100	—	unknown	20:55–05:45 (good, 8.83 h)	79.1° 02:25	9.07	3%	129.5°
2035-09-30 Sun	100	—	unknown	20:50–05:45 (good, 8.92 h)	79.1° 02:20	9.12	0%	140.7°
2035-10-01 Mon	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.1° 02:15	9.17	0%	150.1°
2035-10-02 Tue	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.1° 02:10	9.22	2%	155.6°
2035-10-03 Wed	100	—	unknown	20:40–05:50 (good, 9.17 h)	79.1° 02:05	9.27	6%	155.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-09-04&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.