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 Andromeda Galaxy: 01-26 (94), 01-27 (94), 01-25 (93), 01-28 (93), 01-29 (92) — 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	40	—	unknown	19:00–19:45 (good, 0.75 h)	89.5° 17:00	11.09	95%	74.3°
2035-01-22 Mon	49	—	unknown	19:05–20:55 (good, 1.83 h)	89.6° 17:00	11.06	99%	86.1°
2035-01-23 Tue	62	—	unknown	19:05–22:05 (good, 3.0 h)	89.8° 16:55	11.03	100%	97.8°
2035-01-24 Wed	75	—	unknown	19:05–22:35 (good, 3.5 h)	89.7° 16:50	11.01	98%	109.1°
2035-01-25 Thu	93	—	unknown	19:05–22:45 (good, 3.67 h)	89.6° 16:45	10.98	94%	119.7°
2035-01-26 Fri	94	—	unknown	19:05–22:40 (good, 3.58 h)	89.5° 16:45	10.95	88%	129.0°
2035-01-27 Sat	94	—	unknown	19:10–22:40 (good, 3.5 h)	89.7° 16:40	10.92	81%	136.6°
2035-01-28 Sun	93	—	unknown	19:10–22:45 (good, 3.58 h)	89.8° 16:35	10.89	72%	141.5°
2035-01-29 Mon	92	—	unknown	19:10–22:40 (good, 3.5 h)	89.7° 16:30	10.86	63%	143.2°
2035-01-30 Tue	90	—	unknown	19:10–22:35 (good, 3.42 h)	89.5° 16:25	10.83	53%	141.5°
2035-01-31 Wed	86	—	unknown	19:15–22:30 (good, 3.25 h)	89.6° 16:25	10.8	44%	136.8°
2035-02-01 Thu	84	—	unknown	19:15–22:30 (good, 3.25 h)	89.7° 16:20	10.76	34%	130.2°
2035-02-02 Fri	81	—	unknown	19:15–22:25 (good, 3.17 h)	89.8° 16:15	10.73	26%	122.4°
2035-02-03 Sat	79	—	unknown	19:15–22:20 (good, 3.08 h)	89.7° 16:10	10.7	18%	113.7°
2035-02-04 Sun	77	—	unknown	19:15–22:15 (good, 3.0 h)	89.5° 16:05	10.66	11%	104.4°
2035-02-05 Mon	73	—	unknown	19:20–22:10 (good, 2.83 h)	89.6° 16:05	10.63	6%	94.8°
2035-02-06 Tue	71	—	unknown	19:20–22:10 (good, 2.83 h)	89.8° 16:00	10.59	2%	84.9°
2035-02-07 Wed	69	—	unknown	19:20–22:05 (good, 2.75 h)	89.7° 15:55	10.56	0%	74.9°
2035-02-08 Thu	67	—	unknown	19:20–22:00 (good, 2.67 h)	89.6° 15:50	10.52	0%	65.0°
2035-02-09 Fri	64	—	unknown	19:25–21:55 (good, 2.5 h)	89.5° 15:50	10.48	3%	55.6°
2035-02-10 Sat	59	—	unknown	19:25–21:55 (good, 2.5 h)	89.7° 15:45	10.45	7%	47.2°
2035-02-11 Sun	53	—	unknown	19:25–21:50 (good, 2.42 h)	89.8° 15:40	10.41	14%	40.6°
2035-02-12 Mon	45	—	unknown	19:25–21:35 (good, 2.17 h)	89.7° 15:35	10.37	22%	37.1°
2035-02-13 Tue	37	—	unknown	19:25–21:20 (good, 1.92 h)	89.6° 15:30	10.33	32%	37.8°
2035-02-14 Wed	29	—	unknown	19:30–21:05 (good, 1.58 h)	89.6° 15:30	10.29	43%	42.6°
2035-02-15 Thu	23	—	unknown	19:30–19:35 (good, 0.08 h)	89.7° 15:25	10.25	54%	50.3°
2035-02-16 Fri	20	—	unknown	19:30–21:55 (marginal, 2.42 h)	89.8° 15:20	10.21	66%	60.0°
2035-02-17 Sat	19	—	unknown	19:30–21:45 (marginal, 2.25 h)	89.7° 15:15	10.17	76%	70.7°
2035-02-18 Sun	19	—	unknown	19:35–21:45 (marginal, 2.17 h)	89.5° 15:10	10.13	85%	81.9°
2035-02-19 Mon	22	—	unknown	19:35–20:05 (good, 0.5 h)	89.6° 15:10	10.09	92%	93.4°

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.