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: 08-16 (100), 08-28 (100), 08-29 (100), 08-30 (100), 08-31 (100) — by astronomy; check the weather when the night is within four days.

2035-08-16astronomy score per night — click a bar for that night2035-09-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-08-16 Thu	100	—	unknown	00:25–04:50 (good, 4.42 h)	79.1° 05:15	6.69	96%	91.9°
2035-08-17 Fri	70	—	unknown	01:30–04:50 (good, 3.33 h)	79.1° 05:10	6.75	99%	80.8°
2035-08-18 Sat	55	—	unknown	02:45–04:50 (good, 2.08 h)	79.1° 05:10	6.8	100%	69.6°
2035-08-19 Sun	42	—	unknown	23:25–04:55 (marginal, 5.5 h)	79.1° 05:05	6.86	99%	58.4°
2035-08-20 Mon	32	—	unknown	23:25–04:55 (marginal, 5.5 h)	79.1° 05:00	6.92	96%	47.4°
2035-08-21 Tue	26	—	unknown	23:20–04:55 (marginal, 5.58 h)	79.1° 04:55	6.98	91%	37.1°
2035-08-22 Wed	29	—	unknown	23:10–05:00 (marginal, 5.83 h)	79.1° 04:50	7.03	85%	28.5°
2035-08-23 Thu	39	—	unknown	23:00–05:00 (marginal, 6.0 h)	79.1° 04:50	7.09	76%	24.0°
2035-08-24 Fri	55	—	unknown	23:15–23:20 (good, 0.08 h)	79.1° 04:45	7.15	66%	26.0°
2035-08-25 Sat	82	—	unknown	23:15–05:00 (good, 5.75 h)	79.1° 04:40	7.21	55%	33.7°
2035-08-26 Sun	88	—	unknown	23:10–05:05 (good, 5.92 h)	79.1° 04:35	7.26	44%	44.4°
2035-08-27 Mon	95	—	unknown	23:05–05:05 (good, 6.0 h)	79.1° 04:30	7.32	32%	56.5°
2035-08-28 Tue	100	—	unknown	23:00–05:05 (good, 6.08 h)	79.1° 04:30	7.38	22%	69.3°
2035-08-29 Wed	100	—	unknown	22:55–05:10 (good, 6.25 h)	79.1° 04:25	7.43	13%	82.5°
2035-08-30 Thu	100	—	unknown	22:55–05:10 (good, 6.25 h)	79.1° 04:20	7.49	6%	95.8°
2035-08-31 Fri	100	—	unknown	22:50–05:10 (good, 6.33 h)	79.1° 04:15	7.55	2%	109.0°
2035-09-01 Sat	100	—	unknown	22:45–05:10 (good, 6.42 h)	79.1° 04:15	7.6	0%	121.8°
2035-09-02 Sun	100	—	unknown	22:40–05:15 (good, 6.58 h)	79.1° 04:10	7.66	1%	133.9°
2035-09-03 Mon	100	—	unknown	22:40–05:15 (good, 6.58 h)	79.1° 04:05	7.71	4%	144.6°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-08-16&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.