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: 08-19 (100), 08-20 (100), 08-21 (100), 08-22 (100), 08-23 (100) — by astronomy; check the weather when the night is within four days.

2044-08-18astronomy score per night — click a bar for that night2044-09-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-08-18 Thu	92	—	unknown	23:40–04:55 (good, 5.25 h)	79.2° 05:05	6.85	22%	57.1°
2044-08-19 Fri	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 05:00	6.91	13%	71.1°
2044-08-20 Sat	100	—	unknown	23:30–04:55 (good, 5.42 h)	79.2° 04:55	6.97	6%	85.3°
2044-08-21 Sun	100	—	unknown	23:25–04:55 (good, 5.5 h)	79.2° 04:55	7.02	2%	99.6°
2044-08-22 Mon	100	—	unknown	23:20–05:00 (good, 5.67 h)	79.2° 04:50	7.08	0%	113.7°
2044-08-23 Tue	100	—	unknown	23:20–05:00 (good, 5.67 h)	79.2° 04:45	7.14	1%	127.5°
2044-08-24 Wed	100	—	unknown	23:15–05:00 (good, 5.75 h)	79.2° 04:40	7.2	5%	140.6°
2044-08-25 Thu	100	—	unknown	23:10–05:05 (good, 5.92 h)	79.2° 04:40	7.25	10%	152.6°
2044-08-26 Fri	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.2° 04:35	7.31	18%	162.0°
2044-08-27 Sat	100	—	unknown	23:00–05:05 (good, 6.08 h)	79.2° 04:30	7.37	27%	164.5°
2044-08-28 Sun	100	—	unknown	23:00–05:05 (good, 6.08 h)	79.2° 04:25	7.42	36%	158.3°
2044-08-29 Mon	100	—	unknown	22:55–05:10 (good, 6.25 h)	79.2° 04:20	7.48	46%	148.5°
2044-08-30 Tue	100	—	unknown	22:55–05:10 (good, 6.25 h)	79.2° 04:20	7.54	55%	137.7°
2044-08-31 Wed	100	—	unknown	22:50–05:10 (good, 6.33 h)	79.2° 04:15	7.59	64%	126.6°
2044-09-01 Thu	100	—	unknown	22:50–05:15 (good, 6.42 h)	79.2° 04:10	7.65	73%	115.4°
2044-09-02 Fri	100	—	unknown	22:55–05:15 (good, 6.33 h)	79.2° 04:05	7.7	81%	104.0°
2044-09-03 Sat	100	—	unknown	23:00–05:15 (good, 6.25 h)	79.2° 04:00	7.76	88%	92.5°
2044-09-04 Sun	100	—	unknown	23:50–05:15 (good, 5.42 h)	79.2° 04:00	7.81	94%	80.8°
2044-09-05 Mon	74	—	unknown	01:20–05:20 (good, 4.0 h)	79.2° 03:55	7.87	98%	69.0°
2044-09-06 Tue	61	—	unknown	04:45–05:20 (good, 0.58 h)	79.2° 03:50	7.92	100%	57.0°
2044-09-07 Wed	41	—	unknown	22:20–05:20 (marginal, 7.0 h)	79.2° 03:45	7.98	100%	45.0°
2044-09-08 Thu	27	—	unknown	22:20–05:20 (marginal, 7.0 h)	79.2° 03:45	8.03	98%	33.3°
2044-09-09 Fri	26	—	unknown	22:10–05:25 (marginal, 7.25 h)	79.2° 03:40	8.09	94%	22.5°
2044-09-10 Sat	33	—	unknown	21:55–05:25 (marginal, 7.5 h)	79.2° 03:35	8.14	87%	15.6°
2044-09-11 Sun	44	—	unknown	21:40–05:25 (marginal, 7.75 h)	79.2° 03:30	8.19	79%	18.2°
2044-09-12 Mon	57	—	unknown	21:30–05:25 (marginal, 7.92 h)	79.2° 03:25	8.25	69%	28.1°
2044-09-13 Tue	82	—	unknown	21:55–04:40 (good, 6.75 h)	79.2° 03:25	8.3	58%	40.3°
2044-09-14 Wed	89	—	unknown	21:50–05:30 (good, 7.67 h)	79.2° 03:20	8.35	47%	53.5°
2044-09-15 Thu	98	—	unknown	21:50–05:30 (good, 7.67 h)	79.2° 03:15	8.41	36%	67.0°
2044-09-16 Fri	100	—	unknown	21:45–05:30 (good, 7.75 h)	79.2° 03:10	8.46	25%	80.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-08-18&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.