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: 02-08 (66), 02-07 (65), 02-09 (63), 02-10 (62), 02-06 (59) — by astronomy; check the weather when the night is within four days.

2042-02-05astronomy score per night — click a bar for that night2042-03-06

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-02-05 Wed	53	—	unknown	19:20–21:50 (good, 2.5 h)	89.5° 16:05	10.62	99%	111.1°
2042-02-06 Thu	59	—	unknown	19:20–21:55 (good, 2.58 h)	89.7° 16:00	10.58	97%	120.6°
2042-02-07 Fri	65	—	unknown	19:20–21:55 (good, 2.58 h)	89.8° 15:55	10.55	93%	129.4°
2042-02-08 Sat	66	—	unknown	19:20–21:50 (good, 2.5 h)	89.7° 15:50	10.51	87%	137.2°
2042-02-09 Sun	63	—	unknown	19:25–21:55 (good, 2.5 h)	89.6° 15:45	10.47	80%	143.1°
2042-02-10 Mon	62	—	unknown	19:25–21:50 (good, 2.42 h)	89.6° 15:45	10.44	72%	146.3°
2042-02-11 Tue	59	—	unknown	19:25–21:50 (good, 2.42 h)	89.7° 15:40	10.4	63%	146.0°
2042-02-12 Wed	57	—	unknown	19:25–21:45 (good, 2.33 h)	89.8° 15:35	10.36	54%	142.1°
2042-02-13 Thu	55	—	unknown	19:30–21:40 (good, 2.17 h)	89.7° 15:30	10.32	44%	135.4°
2042-02-14 Fri	53	—	unknown	19:30–21:35 (good, 2.08 h)	89.5° 15:25	10.28	34%	126.7°
2042-02-15 Sat	50	—	unknown	19:30–21:30 (good, 2.0 h)	89.6° 15:25	10.24	24%	116.7°
2042-02-16 Sun	49	—	unknown	19:30–21:30 (good, 2.0 h)	89.8° 15:20	10.2	15%	105.6°
2042-02-17 Mon	47	—	unknown	19:30–21:25 (good, 1.92 h)	89.8° 15:15	10.16	8%	93.9°
2042-02-18 Tue	44	—	unknown	19:35–21:20 (good, 1.75 h)	89.7° 15:10	10.12	3%	81.7°
2042-02-19 Wed	43	—	unknown	19:35–21:15 (good, 1.67 h)	89.5° 15:10	10.08	0%	69.5°
2042-02-20 Thu	41	—	unknown	19:35–21:15 (good, 1.67 h)	89.7° 15:05	10.04	1%	57.5°
2042-02-21 Fri	39	—	unknown	19:35–21:10 (good, 1.58 h)	89.8° 15:00	9.99	4%	46.7°
2042-02-22 Sat	34	—	unknown	19:40–21:05 (good, 1.42 h)	89.8° 14:55	9.95	10%	38.2°
2042-02-23 Sun	29	—	unknown	19:40–20:50 (good, 1.17 h)	89.6° 14:50	9.91	18%	33.6°
2042-02-24 Mon	23	—	unknown	19:40–20:40 (good, 1.0 h)	89.6° 14:50	9.86	28%	34.4°
2042-02-25 Tue	18	—	unknown	19:40–20:25 (good, 0.75 h)	89.7° 14:45	9.82	39%	39.8°
2042-02-26 Wed	14	—	unknown	19:45–21:20 (marginal, 1.58 h)	89.8° 14:40	9.78	50%	48.0°
2042-02-27 Thu	12	—	unknown	19:45–21:10 (marginal, 1.42 h)	89.7° 14:35	9.73	60%	57.5°
2042-02-28 Fri	11	—	unknown	19:45–21:00 (marginal, 1.25 h)	89.5° 14:30	9.69	70%	67.7°
2042-03-01 Sat	10	—	unknown	19:45–21:00 (marginal, 1.25 h)	89.6° 14:30	9.64	79%	78.0°
2042-03-02 Sun	11	—	unknown	19:45–21:00 (marginal, 1.25 h)	89.8° 14:25	9.6	86%	88.3°
2042-03-03 Mon	12	—	unknown	19:15–21:00 (marginal, 1.75 h)	89.8° 14:20	9.55	92%	98.6°
2042-03-04 Tue	13	—	unknown	19:50–20:00 (good, 0.17 h)	89.7° 14:15	9.5	97%	108.5°
2042-03-05 Wed	14	—	unknown	19:50–20:05 (good, 0.25 h)	89.5° 14:15	9.46	99%	118.1°
2042-03-06 Thu	13	—	unknown	19:50–20:05 (good, 0.25 h)	89.7° 14:10	9.41	100%	127.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-02-05&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.