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: 09-06 (100), 09-07 (100), 09-08 (100), 09-09 (100), 09-10 (100) — by astronomy; check the weather when the night is within four days.

2045-09-06astronomy score per night — click a bar for that night2045-10-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-09-06 Wed	100	—	unknown	22:25–05:20 (good, 6.92 h)	79.2° 03:50	7.91	23%	73.9°
2045-09-07 Thu	100	—	unknown	22:20–05:20 (good, 7.0 h)	79.2° 03:45	7.96	14%	88.0°
2045-09-08 Fri	100	—	unknown	22:15–05:20 (good, 7.08 h)	79.2° 03:45	8.02	7%	102.5°
2045-09-09 Sat	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.2° 03:40	8.07	2%	117.0°
2045-09-10 Sun	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.2° 03:35	8.13	0%	131.4°
2045-09-11 Mon	100	—	unknown	22:05–05:25 (good, 7.33 h)	79.2° 03:30	8.18	1%	145.3°
2045-09-12 Tue	100	—	unknown	22:00–05:25 (good, 7.42 h)	79.2° 03:30	8.23	5%	157.7°
2045-09-13 Wed	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.2° 03:25	8.29	11%	165.3°
2045-09-14 Thu	100	—	unknown	21:50–05:30 (good, 7.67 h)	79.2° 03:20	8.34	20%	161.9°
2045-09-15 Fri	100	—	unknown	21:50–05:30 (good, 7.67 h)	79.2° 03:15	8.39	29%	151.8°
2045-09-16 Sat	100	—	unknown	21:45–05:30 (good, 7.75 h)	79.2° 03:10	8.45	39%	140.3°
2045-09-17 Sun	100	—	unknown	21:45–05:35 (good, 7.83 h)	79.2° 03:10	8.5	49%	128.5°
2045-09-18 Mon	100	—	unknown	21:45–05:35 (good, 7.83 h)	79.2° 03:05	8.55	58%	116.8°
2045-09-19 Tue	100	—	unknown	21:45–05:35 (good, 7.83 h)	79.2° 03:00	8.6	68%	105.1°
2045-09-20 Wed	100	—	unknown	21:50–05:35 (good, 7.75 h)	79.2° 02:55	8.65	76%	93.6°
2045-09-21 Thu	100	—	unknown	22:10–05:40 (good, 7.5 h)	79.2° 02:50	8.7	84%	82.1°
2045-09-22 Fri	100	—	unknown	23:35–05:40 (good, 6.08 h)	79.2° 02:50	8.75	90%	70.7°
2045-09-23 Sat	99	—	unknown	02:35–05:40 (good, 3.08 h)	79.2° 02:45	8.81	95%	59.3°
2045-09-24 Sun	60	—	unknown	05:15–05:40 (good, 0.42 h)	79.2° 02:40	8.86	98%	47.9°
2045-09-25 Mon	42	—	unknown	21:20–05:40 (marginal, 8.33 h)	79.2° 02:35	8.91	100%	36.7°
2045-09-26 Tue	29	—	unknown	03:25–05:45 (marginal, 2.33 h)	79.2° 02:35	8.96	100%	26.1°
2045-09-27 Wed	27	—	unknown	21:00–00:35 (marginal, 3.58 h)	79.2° 02:30	9.0	97%	17.3°
2045-09-28 Thu	33	—	unknown	20:45–01:55 (marginal, 5.17 h)	79.2° 02:25	9.05	93%	14.8°
2045-09-29 Fri	43	—	unknown	20:40–05:45 (marginal, 9.08 h)	79.2° 02:20	9.1	87%	21.4°
2045-09-30 Sat	66	—	unknown	20:50–21:00 (good, 0.17 h)	79.2° 02:15	9.15	79%	32.0°
2045-10-01 Sun	83	—	unknown	20:45–01:40 (good, 4.92 h)	79.2° 02:15	9.2	70%	44.0°
2045-10-02 Mon	91	—	unknown	20:40–05:30 (good, 8.83 h)	79.2° 02:10	9.25	59%	56.7°
2045-10-03 Tue	100	—	unknown	20:40–05:50 (good, 9.17 h)	79.2° 02:05	9.29	48%	69.9°
2045-10-04 Wed	100	—	unknown	20:35–05:55 (good, 9.33 h)	79.2° 02:00	9.34	37%	83.4°
2045-10-05 Thu	100	—	unknown	20:30–05:55 (good, 9.42 h)	79.2° 01:55	9.39	26%	97.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-09-06&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.