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: 01-03 (100), 01-04 (100), 01-05 (100), 01-06 (100), 01-07 (100) — by astronomy; check the weather when the night is within four days.

2037-01-03astronomy score per night — click a bar for that night2037-02-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-01-03 Sat	100	—	unknown	18:45–23:40 (good, 4.92 h)	89.7° 18:10	11.42	95%	99.3°
2037-01-04 Sun	100	—	unknown	18:45–23:55 (good, 5.17 h)	89.5° 18:05	11.41	89%	110.7°
2037-01-05 Mon	100	—	unknown	18:45–00:00 (good, 5.25 h)	89.6° 18:05	11.4	80%	121.2°
2037-01-06 Tue	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.8° 18:00	11.38	70%	130.4°
2037-01-07 Wed	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.8° 17:55	11.37	59%	137.4°
2037-01-08 Thu	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.6° 17:50	11.35	48%	141.1°
2037-01-09 Fri	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.5° 17:50	11.34	37%	140.9°
2037-01-10 Sat	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.7° 17:45	11.32	27%	137.0°
2037-01-11 Sun	100	—	unknown	18:55–23:50 (good, 4.92 h)	89.8° 17:40	11.3	19%	130.5°
2037-01-12 Mon	100	—	unknown	18:55–23:45 (good, 4.83 h)	89.7° 17:35	11.28	11%	122.5°
2037-01-13 Tue	100	—	unknown	18:55–23:40 (good, 4.75 h)	89.6° 17:30	11.26	6%	113.6°
2037-01-14 Wed	100	—	unknown	18:55–23:35 (good, 4.67 h)	89.6° 17:30	11.24	2%	104.3°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-01-03&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.