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: 01-26 (100), 01-27 (100), 01-28 (99), 01-25 (98), 01-29 (98) — by astronomy; check the weather when the night is within four days.

2035-01-21astronomy score per night — click a bar for that night2035-02-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-01-21 Sun	35	—	unknown	19:00–23:25 (marginal, 4.42 h)	79.1° 17:55	11.09	95%	65.9°
2035-01-22 Mon	46	—	unknown	19:05–20:40 (good, 1.58 h)	79.1° 17:50	11.06	99%	79.3°
2035-01-23 Tue	61	—	unknown	19:05–21:55 (good, 2.83 h)	79.1° 17:45	11.03	100%	92.8°
2035-01-24 Wed	77	—	unknown	19:05–22:50 (good, 3.75 h)	79.1° 17:40	11.01	98%	106.0°
2035-01-25 Thu	98	—	unknown	19:05–23:00 (good, 3.92 h)	79.1° 17:40	10.98	94%	118.7°
2035-01-26 Fri	100	—	unknown	19:05–22:55 (good, 3.83 h)	79.1° 17:35	10.95	88%	130.6°
2035-01-27 Sat	100	—	unknown	19:10–22:55 (good, 3.75 h)	79.1° 17:30	10.92	81%	141.5°
2035-01-28 Sun	99	—	unknown	19:10–22:55 (good, 3.75 h)	79.1° 17:25	10.89	72%	150.4°
2035-01-29 Mon	98	—	unknown	19:10–22:55 (good, 3.75 h)	79.1° 17:20	10.86	63%	156.0°
2035-01-30 Tue	96	—	unknown	19:10–22:50 (good, 3.67 h)	79.1° 17:20	10.83	53%	156.2°
2035-01-31 Wed	93	—	unknown	19:15–22:45 (good, 3.5 h)	79.1° 17:15	10.8	44%	151.2°
2035-02-01 Thu	91	—	unknown	19:15–22:45 (good, 3.5 h)	79.1° 17:10	10.76	34%	143.2°
2035-02-02 Fri	89	—	unknown	19:15–22:40 (good, 3.42 h)	79.1° 17:05	10.73	26%	133.7°
2035-02-03 Sat	88	—	unknown	19:15–22:35 (good, 3.33 h)	79.1° 17:00	10.7	18%	123.5°
2035-02-04 Sun	86	—	unknown	19:15–22:30 (good, 3.25 h)	79.1° 17:00	10.66	11%	112.8°
2035-02-05 Mon	82	—	unknown	19:20–22:25 (good, 3.08 h)	79.1° 16:55	10.63	6%	101.7°
2035-02-06 Tue	80	—	unknown	19:20–22:25 (good, 3.08 h)	79.1° 16:50	10.59	2%	90.3°
2035-02-07 Wed	78	—	unknown	19:20–22:20 (good, 3.0 h)	79.1° 16:45	10.56	0%	78.8°
2035-02-08 Thu	76	—	unknown	19:20–22:15 (good, 2.92 h)	79.1° 16:45	10.52	0%	67.1°
2035-02-09 Fri	72	—	unknown	19:25–22:10 (good, 2.75 h)	79.1° 16:40	10.48	3%	55.4°
2035-02-10 Sat	67	—	unknown	19:25–22:05 (good, 2.67 h)	79.1° 16:35	10.45	7%	44.1°
2035-02-11 Sun	59	—	unknown	19:25–22:05 (good, 2.67 h)	79.1° 16:30	10.41	14%	33.7°
2035-02-12 Mon	50	—	unknown	19:25–21:50 (good, 2.42 h)	79.1° 16:25	10.37	22%	25.8°
2035-02-13 Tue	40	—	unknown	19:25–21:40 (good, 2.25 h)	79.1° 16:25	10.33	32%	23.4°
2035-02-14 Wed	30	—	unknown	19:30–21:00 (good, 1.5 h)	79.1° 16:20	10.29	43%	28.1°
2035-02-15 Thu	23	—	unknown	19:30–22:10 (marginal, 2.67 h)	79.1° 16:15	10.25	54%	37.5°
2035-02-16 Fri	19	—	unknown	19:30–22:00 (marginal, 2.5 h)	79.1° 16:10	10.21	66%	49.1°
2035-02-17 Sat	19	—	unknown	19:30–21:55 (marginal, 2.42 h)	79.1° 16:05	10.17	76%	61.6°
2035-02-18 Sun	19	—	unknown	19:35–21:50 (marginal, 2.25 h)	79.1° 16:05	10.13	85%	74.6°
2035-02-19 Mon	23	—	unknown	19:35–19:55 (good, 0.33 h)	79.1° 16:00	10.09	92%	87.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-01-21&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.