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: 12-22 (100), 12-23 (100), 12-24 (100), 12-25 (100), 12-26 (100) — by astronomy; check the weather when the night is within four days.

2035-12-22astronomy score per night — click a bar for that night2036-01-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-12-22 Sat	100	—	unknown	18:35–01:10 (good, 6.58 h)	89.7° 19:00	11.51	37%	141.2°
2035-12-23 Sun	100	—	unknown	18:40–01:05 (good, 6.42 h)	89.5° 18:55	11.51	28%	142.2°
2035-12-24 Mon	100	—	unknown	18:40–01:00 (good, 6.33 h)	89.6° 18:55	11.5	19%	139.7°
2035-12-25 Tue	100	—	unknown	18:40–01:00 (good, 6.33 h)	89.8° 18:50	11.5	12%	134.5°
2035-12-26 Wed	100	—	unknown	18:40–00:55 (good, 6.25 h)	89.7° 18:45	11.5	7%	127.5°
2035-12-27 Thu	100	—	unknown	18:40–00:50 (good, 6.17 h)	89.6° 18:40	11.49	3%	119.4°
2035-12-28 Fri	100	—	unknown	18:40–00:45 (good, 6.08 h)	89.5° 18:40	11.49	0%	110.6°
2035-12-29 Sat	100	—	unknown	18:40–00:45 (good, 6.08 h)	89.7° 18:35	11.48	0%	101.5°
2035-12-30 Sun	100	—	unknown	18:40–00:40 (good, 6.0 h)	89.8° 18:30	11.47	2%	92.2°
2035-12-31 Mon	100	—	unknown	18:45–00:35 (good, 5.83 h)	89.7° 18:25	11.46	5%	82.8°
2036-01-01 Tue	100	—	unknown	18:45–00:30 (good, 5.75 h)	89.5° 18:20	11.45	10%	73.6°
2036-01-02 Wed	100	—	unknown	18:45–00:25 (good, 5.67 h)	89.6° 18:20	11.44	16%	64.6°
2036-01-03 Thu	95	—	unknown	18:45–00:25 (good, 5.67 h)	89.7° 18:15	11.43	23%	56.1°
2036-01-04 Fri	87	—	unknown	18:45–00:20 (good, 5.58 h)	89.8° 18:10	11.42	32%	48.4°
2036-01-05 Sat	80	—	unknown	18:45–00:15 (good, 5.5 h)	89.7° 18:05	11.41	42%	42.2°
2036-01-06 Sun	68	—	unknown	18:45–23:45 (good, 5.0 h)	89.5° 18:00	11.39	52%	38.5°
2036-01-07 Mon	50	—	unknown	18:50–00:40 (marginal, 5.83 h)	89.6° 18:00	11.38	62%	38.2°
2036-01-08 Tue	39	—	unknown	18:50–00:25 (marginal, 5.58 h)	89.8° 17:55	11.36	73%	41.9°
2036-01-09 Wed	34	—	unknown	18:50–00:10 (marginal, 5.33 h)	89.7° 17:50	11.35	82%	48.9°
2036-01-10 Thu	36	—	unknown	18:50–23:55 (marginal, 5.08 h)	89.6° 17:45	11.33	90%	58.3°
2036-01-11 Fri	43	—	unknown	18:50–18:55 (good, 0.08 h)	89.5° 17:45	11.31	96%	69.2°
2036-01-12 Sat	55	—	unknown	18:55–20:55 (good, 2.0 h)	89.7° 17:40	11.29	100%	81.0°
2036-01-13 Sun	71	—	unknown	18:55–22:15 (good, 3.33 h)	89.8° 17:35	11.28	100%	93.1°
2036-01-14 Mon	87	—	unknown	18:55–23:15 (good, 4.33 h)	89.7° 17:30	11.26	97%	105.0°
2036-01-15 Tue	100	—	unknown	18:55–23:20 (good, 4.42 h)	89.6° 17:25	11.23	91%	116.2°
2036-01-16 Wed	100	—	unknown	18:55–23:20 (good, 4.42 h)	89.6° 17:25	11.21	83%	126.3°
2036-01-17 Thu	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.7° 17:20	11.19	74%	134.5°
2036-01-18 Fri	100	—	unknown	19:00–23:25 (good, 4.42 h)	89.8° 17:15	11.17	64%	140.1°
2036-01-19 Sat	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.7° 17:10	11.14	54%	142.1°
2036-01-20 Sun	100	—	unknown	19:00–23:15 (good, 4.25 h)	89.5° 17:05	11.12	43%	140.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-12-22&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.