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: 01-31 (86), 02-01 (83), 02-02 (80), 02-03 (78), 02-04 (73) — by astronomy; check the weather when the night is within four days.

2030-01-31astronomy score per night — click a bar for that night2030-03-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-01-31 Thu	86	—	unknown	19:15–22:30 (good, 3.25 h)	89.5° 16:20	10.79	4%	95.4°
2030-02-01 Fri	83	—	unknown	19:15–22:25 (good, 3.17 h)	89.6° 16:20	10.76	1%	83.2°
2030-02-02 Sat	80	—	unknown	19:15–22:25 (good, 3.17 h)	89.7° 16:15	10.72	0%	71.4°
2030-02-03 Sun	78	—	unknown	19:15–22:20 (good, 3.08 h)	89.7° 16:10	10.69	2%	60.1°
2030-02-04 Mon	73	—	unknown	19:20–22:15 (good, 2.92 h)	89.6° 16:05	10.65	6%	49.6°
2030-02-05 Tue	67	—	unknown	19:20–22:10 (good, 2.83 h)	89.5° 16:00	10.62	12%	40.4°
2030-02-06 Wed	58	—	unknown	19:20–22:05 (good, 2.75 h)	89.6° 16:00	10.58	19%	33.3°
2030-02-07 Thu	48	—	unknown	19:20–21:50 (good, 2.5 h)	89.7° 15:55	10.55	27%	29.4°
2030-02-08 Fri	38	—	unknown	19:20–21:35 (good, 2.25 h)	89.7° 15:50	10.51	36%	29.9°
2030-02-09 Sat	31	—	unknown	19:25–20:35 (good, 1.17 h)	89.6° 15:45	10.48	45%	34.3°
2030-02-10 Sun	25	—	unknown	19:25–22:20 (marginal, 2.92 h)	89.5° 15:45	10.44	54%	41.4°
2030-02-11 Mon	21	—	unknown	19:25–22:10 (marginal, 2.75 h)	89.7° 15:40	10.4	64%	50.0°
2030-02-12 Tue	20	—	unknown	19:25–22:00 (marginal, 2.58 h)	89.7° 15:35	10.36	72%	59.7°
2030-02-13 Wed	20	—	unknown	19:30–21:55 (marginal, 2.42 h)	89.7° 15:30	10.32	81%	70.0°
2030-02-14 Thu	22	—	unknown	19:30–21:55 (marginal, 2.42 h)	89.5° 15:25	10.28	88%	80.9°
2030-02-15 Fri	25	—	unknown	19:30–20:10 (good, 0.67 h)	89.6° 15:25	10.24	94%	92.1°
2030-02-16 Sat	30	—	unknown	19:30–21:00 (good, 1.5 h)	89.7° 15:20	10.2	98%	103.6°
2030-02-17 Sun	34	—	unknown	19:30–21:05 (good, 1.58 h)	89.7° 15:15	10.16	100%	115.2°
2030-02-18 Mon	36	—	unknown	19:35–21:10 (good, 1.58 h)	89.6° 15:10	10.12	99%	126.5°
2030-02-19 Tue	40	—	unknown	19:35–21:05 (good, 1.5 h)	89.5° 15:05	10.08	96%	137.1°
2030-02-20 Wed	40	—	unknown	19:35–21:05 (good, 1.5 h)	89.6° 15:05	10.04	91%	145.8°
2030-02-21 Thu	39	—	unknown	19:35–21:10 (good, 1.58 h)	89.7° 15:00	10.0	83%	150.5°
2030-02-22 Fri	36	—	unknown	19:40–21:05 (good, 1.42 h)	89.7° 14:55	9.95	74%	149.3°
2030-02-23 Sat	35	—	unknown	19:40–21:00 (good, 1.33 h)	89.6° 14:50	9.91	63%	142.8°
2030-02-24 Sun	33	—	unknown	19:40–20:55 (good, 1.25 h)	89.5° 14:50	9.87	52%	133.3°
2030-02-25 Mon	31	—	unknown	19:40–20:50 (good, 1.17 h)	89.6° 14:45	9.82	40%	122.2°
2030-02-26 Tue	29	—	unknown	19:45–20:50 (good, 1.08 h)	89.7° 14:40	9.78	30%	110.6°
2030-02-27 Wed	28	—	unknown	19:45–20:45 (good, 1.0 h)	89.7° 14:35	9.74	20%	98.7°
2030-02-28 Thu	26	—	unknown	19:45–20:40 (good, 0.92 h)	89.6° 14:30	9.69	12%	86.8°
2030-03-01 Fri	25	—	unknown	19:45–20:35 (good, 0.83 h)	89.5° 14:30	9.65	6%	75.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-01-31&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.