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: 01-09 (100), 01-10 (100), 01-11 (100), 01-12 (100), 01-26 (94) — by astronomy; check the weather when the night is within four days.

2035-01-09astronomy score per night — click a bar for that night2035-02-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-01-09 Tue	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.8° 17:50	11.34	0%	91.8°
2035-01-10 Wed	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.7° 17:45	11.33	2%	82.0°
2035-01-11 Thu	100	—	unknown	18:50–23:50 (good, 5.0 h)	89.6° 17:40	11.31	5%	72.1°
2035-01-12 Fri	100	—	unknown	18:55–23:45 (good, 4.83 h)	89.5° 17:40	11.29	11%	62.4°
2035-01-13 Sat	93	—	unknown	18:55–23:45 (good, 4.83 h)	89.7° 17:35	11.27	18%	53.3°
2035-01-14 Sun	88	—	unknown	18:55–23:40 (good, 4.75 h)	89.8° 17:30	11.25	26%	45.3°
2035-01-15 Mon	79	—	unknown	18:55–23:35 (good, 4.67 h)	89.7° 17:25	11.23	36%	39.4°
2035-01-16 Tue	61	—	unknown	18:55–23:05 (good, 4.17 h)	89.5° 17:20	11.21	47%	36.7°
2035-01-17 Wed	45	—	unknown	19:00–20:25 (good, 1.42 h)	89.6° 17:20	11.18	58%	38.4°
2035-01-18 Thu	36	—	unknown	19:00–23:45 (marginal, 4.75 h)	89.7° 17:15	11.16	69%	44.1°
2035-01-19 Fri	32	—	unknown	19:00–23:30 (marginal, 4.5 h)	89.8° 17:10	11.14	80%	52.7°
2035-01-20 Sat	33	—	unknown	19:00–23:20 (marginal, 4.33 h)	89.7° 17:05	11.11	88%	63.0°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-01-09&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.