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: 10-26 (100), 10-27 (100), 10-28 (100), 10-29 (100), 10-30 (100) — by astronomy; check the weather when the night is within four days.

2040-10-25astronomy score per night — click a bar for that night2040-11-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2040-10-25 Thu	98	—	unknown	20:00–04:00 (good, 8.0 h)	79.2° 00:40	10.26	69%	67.1°
2040-10-26 Fri	100	—	unknown	20:00–05:25 (good, 9.42 h)	79.2° 00:35	10.3	60%	78.1°
2040-10-27 Sat	100	—	unknown	19:55–04:45 (good, 9.83 h)	79.2° 00:30	10.34	51%	89.1°
2040-10-28 Sun	100	—	unknown	18:55–04:50 (good, 9.92 h)	79.2° 23:25	10.38	42%	100.1°
2040-10-29 Mon	100	—	unknown	18:55–04:50 (good, 9.92 h)	79.2° 23:20	10.41	32%	111.2°
2040-10-30 Tue	100	—	unknown	18:55–04:50 (good, 9.92 h)	79.2° 23:20	10.45	24%	122.2°
2040-10-31 Wed	100	—	unknown	18:55–04:45 (good, 9.83 h)	79.2° 23:15	10.49	16%	133.2°
2040-11-01 Thu	100	—	unknown	18:50–04:40 (good, 9.83 h)	79.2° 23:10	10.52	9%	143.7°
2040-11-02 Fri	100	—	unknown	18:50–04:40 (good, 9.83 h)	79.2° 23:05	10.56	4%	152.9°
2040-11-03 Sat	100	—	unknown	18:50–04:35 (good, 9.75 h)	79.2° 23:00	10.59	1%	158.4°
2040-11-04 Sun	100	—	unknown	18:50–04:30 (good, 9.67 h)	79.2° 23:00	10.63	0%	156.8°
2040-11-05 Mon	100	—	unknown	18:45–04:25 (good, 9.67 h)	79.2° 22:55	10.66	2%	148.7°
2040-11-06 Tue	100	—	unknown	18:45–04:25 (good, 9.67 h)	79.2° 22:50	10.7	6%	137.6°
2040-11-07 Wed	100	—	unknown	18:45–04:20 (good, 9.58 h)	79.2° 22:45	10.73	12%	125.2°
2040-11-08 Thu	100	—	unknown	18:45–04:15 (good, 9.5 h)	79.2° 22:45	10.76	21%	112.2°
2040-11-09 Fri	100	—	unknown	18:45–04:10 (good, 9.42 h)	79.2° 22:40	10.8	31%	99.0°
2040-11-10 Sat	100	—	unknown	18:45–04:05 (good, 9.33 h)	79.2° 22:35	10.83	42%	85.7°
2040-11-11 Sun	100	—	unknown	18:40–04:05 (good, 9.42 h)	79.2° 22:30	10.86	53%	72.6°
2040-11-12 Mon	100	—	unknown	18:40–04:00 (good, 9.33 h)	79.2° 22:25	10.89	64%	59.7°
2040-11-13 Tue	90	—	unknown	21:50–03:55 (good, 6.08 h)	79.2° 22:25	10.92	75%	47.3°
2040-11-14 Wed	81	—	unknown	03:10–03:50 (good, 0.67 h)	79.2° 22:20	10.95	84%	35.8°
2040-11-15 Thu	44	—	unknown	18:40–04:05 (marginal, 9.42 h)	79.2° 22:15	10.98	91%	26.4°
2040-11-16 Fri	31	—	unknown	23:45–03:40 (marginal, 3.92 h)	79.2° 22:10	11.0	96%	21.4°
2040-11-17 Sat	29	—	unknown	18:40–21:05 (marginal, 2.42 h)	79.2° 22:05	11.03	99%	23.6°
2040-11-18 Sun	31	—	unknown	18:35–21:35 (marginal, 3.0 h)	79.2° 22:05	11.06	100%	31.3°
2040-11-19 Mon	47	—	unknown	18:35–00:45 (marginal, 6.17 h)	79.2° 22:00	11.08	99%	41.3°
2040-11-20 Tue	62	—	unknown	18:35–19:55 (good, 1.33 h)	79.2° 21:55	11.11	95%	52.1°
2040-11-21 Wed	95	—	unknown	18:35–22:20 (good, 3.75 h)	79.2° 21:50	11.13	90%	63.2°
2040-11-22 Thu	100	—	unknown	18:35–00:55 (good, 6.33 h)	79.2° 21:50	11.16	84%	74.3°
2040-11-23 Fri	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.2° 21:45	11.18	76%	85.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2040-10-25&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.