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: 01-15 (100), 01-16 (100), 01-17 (100), 01-18 (100), 01-19 (97) — by astronomy; check the weather when the night is within four days.

2037-01-15astronomy score per night — click a bar for that night2037-02-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-01-15 Thu	100	—	unknown	18:55–23:35 (good, 4.67 h)	89.7° 17:25	11.22	0%	94.9°
2037-01-16 Fri	100	—	unknown	18:55–23:30 (good, 4.58 h)	89.8° 17:20	11.2	0%	85.4°
2037-01-17 Sat	100	—	unknown	19:00–23:25 (good, 4.42 h)	89.7° 17:15	11.17	2%	76.1°
2037-01-18 Sun	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.5° 17:10	11.15	6%	67.2°
2037-01-19 Mon	97	—	unknown	19:00–23:15 (good, 4.25 h)	89.6° 17:10	11.12	11%	58.7°
2037-01-20 Tue	93	—	unknown	19:00–23:15 (good, 4.25 h)	89.8° 17:05	11.1	17%	51.1°
2037-01-21 Wed	85	—	unknown	19:05–23:10 (good, 4.08 h)	89.8° 17:00	11.07	25%	44.8°
2037-01-22 Thu	71	—	unknown	19:05–22:50 (good, 3.75 h)	89.6° 16:55	11.05	34%	40.3°
2037-01-23 Fri	57	—	unknown	19:05–22:35 (good, 3.5 h)	89.5° 16:55	11.02	43%	38.6°
2037-01-24 Sat	44	—	unknown	19:05–21:10 (good, 2.08 h)	89.7° 16:50	10.99	53%	40.1°
2037-01-25 Sun	36	—	unknown	19:05–23:20 (marginal, 4.25 h)	89.8° 16:45	10.96	63%	44.7°
2037-01-26 Mon	31	—	unknown	19:10–23:05 (marginal, 3.92 h)	89.7° 16:40	10.93	73%	51.8°
2037-01-27 Tue	29	—	unknown	19:10–22:55 (marginal, 3.75 h)	89.6° 16:35	10.9	82%	60.8°
2037-01-28 Wed	32	—	unknown	19:10–22:55 (marginal, 3.75 h)	89.6° 16:35	10.87	90%	71.1°
2037-01-29 Thu	38	—	unknown	19:10–20:05 (good, 0.92 h)	89.7° 16:30	10.84	96%	82.3°
2037-01-30 Fri	47	—	unknown	19:10–21:10 (good, 2.0 h)	89.8° 16:25	10.81	99%	94.0°
2037-01-31 Sat	57	—	unknown	19:15–22:05 (good, 2.83 h)	89.7° 16:20	10.78	100%	105.7°
2037-02-01 Sun	67	—	unknown	19:15–22:10 (good, 2.92 h)	89.5° 16:15	10.75	97%	117.0°
2037-02-02 Mon	76	—	unknown	19:15–22:10 (good, 2.92 h)	89.6° 16:15	10.71	92%	127.2°
2037-02-03 Tue	76	—	unknown	19:15–22:10 (good, 2.92 h)	89.8° 16:10	10.68	84%	135.4°
2037-02-04 Wed	74	—	unknown	19:20–22:15 (good, 2.92 h)	89.8° 16:05	10.64	74%	140.4°
2037-02-05 Thu	73	—	unknown	19:20–22:10 (good, 2.83 h)	89.6° 16:00	10.61	64%	141.3°
2037-02-06 Fri	70	—	unknown	19:20–22:05 (good, 2.75 h)	89.5° 16:00	10.57	53%	138.2°
2037-02-07 Sat	68	—	unknown	19:20–22:05 (good, 2.75 h)	89.7° 15:55	10.54	43%	132.2°
2037-02-08 Sun	66	—	unknown	19:20–22:00 (good, 2.67 h)	89.8° 15:50	10.5	33%	124.4°
2037-02-09 Mon	63	—	unknown	19:25–21:55 (good, 2.5 h)	89.7° 15:45	10.46	24%	115.7°
2037-02-10 Tue	61	—	unknown	19:25–21:50 (good, 2.42 h)	89.6° 15:40	10.43	16%	106.6°
2037-02-11 Wed	59	—	unknown	19:25–21:45 (good, 2.33 h)	89.6° 15:40	10.39	9%	97.2°
2037-02-12 Thu	57	—	unknown	19:25–21:45 (good, 2.33 h)	89.7° 15:35	10.35	4%	87.8°
2037-02-13 Fri	53	—	unknown	19:30–21:40 (good, 2.17 h)	89.8° 15:30	10.31	1%	78.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-01-15&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.