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: 07-17 (100), 07-18 (100), 07-19 (100), 07-20 (100), 07-21 (100) — by astronomy; check the weather when the night is within four days.

2042-07-10astronomy score per night — click a bar for that night2042-08-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-07-10 Thu	56	—	unknown	00:45–03:55 (good, 3.17 h)	89.8° 06:50	4.8	42%	32.9°
2042-07-11 Fri	65	—	unknown	00:40–03:55 (good, 3.25 h)	89.8° 06:45	4.84	31%	34.4°
2042-07-12 Sat	77	—	unknown	00:40–03:55 (good, 3.25 h)	89.7° 06:40	4.88	21%	40.4°
2042-07-13 Sun	86	—	unknown	00:35–03:55 (good, 3.33 h)	89.5° 06:40	4.92	13%	49.2°
2042-07-14 Mon	94	—	unknown	00:30–04:00 (good, 3.5 h)	89.7° 06:35	4.96	6%	59.4°
2042-07-15 Tue	97	—	unknown	00:25–04:00 (good, 3.58 h)	89.8° 06:30	5.0	2%	70.3°
2042-07-16 Wed	99	—	unknown	00:20–04:00 (good, 3.67 h)	89.8° 06:25	5.05	0%	81.3°
2042-07-17 Thu	100	—	unknown	00:20–04:05 (good, 3.75 h)	89.6° 06:20	5.09	1%	92.3°
2042-07-18 Fri	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.6° 06:20	5.14	3%	103.0°
2042-07-19 Sat	100	—	unknown	00:10–04:05 (good, 3.92 h)	89.7° 06:15	5.18	8%	113.4°
2042-07-20 Sun	100	—	unknown	00:05–04:05 (good, 4.0 h)	89.8° 06:10	5.23	14%	123.1°
2042-07-21 Mon	100	—	unknown	00:00–04:10 (good, 4.17 h)	89.7° 06:05	5.28	21%	131.9°
2042-07-22 Tue	100	—	unknown	00:00–04:10 (good, 4.17 h)	89.6° 06:00	5.33	29%	139.4°
2042-07-23 Wed	100	—	unknown	23:55–04:10 (good, 4.25 h)	89.6° 06:00	5.38	38%	144.9°
2042-07-24 Thu	100	—	unknown	23:55–04:15 (good, 4.33 h)	89.8° 05:55	5.43	47%	147.3°
2042-07-25 Fri	100	—	unknown	23:50–04:15 (good, 4.42 h)	89.8° 05:50	5.48	57%	146.0°
2042-07-26 Sat	100	—	unknown	23:50–04:15 (good, 4.42 h)	89.7° 05:45	5.53	66%	141.3°
2042-07-27 Sun	100	—	unknown	23:45–04:20 (good, 4.58 h)	89.5° 05:40	5.58	75%	134.0°
2042-07-28 Mon	100	—	unknown	23:45–04:20 (good, 4.58 h)	89.7° 05:40	5.64	84%	125.0°
2042-07-29 Tue	100	—	unknown	23:45–04:20 (good, 4.58 h)	89.8° 05:35	5.69	90%	114.8°
2042-07-30 Wed	100	—	unknown	23:45–04:25 (good, 4.67 h)	89.8° 05:30	5.74	96%	103.8°
2042-07-31 Thu	80	—	unknown	23:55–04:25 (good, 4.5 h)	89.6° 05:25	5.8	99%	92.3°
2042-08-01 Fri	67	—	unknown	00:55–04:25 (good, 3.5 h)	89.5° 05:25	5.85	100%	80.5°
2042-08-02 Sat	54	—	unknown	02:25–04:25 (good, 2.0 h)	89.7° 05:20	5.91	98%	68.6°
2042-08-03 Sun	44	—	unknown	22:45–04:30 (marginal, 5.75 h)	89.8° 05:15	5.97	93%	57.1°
2042-08-04 Mon	41	—	unknown	22:40–04:30 (marginal, 5.83 h)	89.7° 05:10	6.02	86%	46.5°
2042-08-05 Tue	45	—	unknown	22:30–04:30 (marginal, 6.0 h)	89.6° 05:05	6.08	77%	38.0°
2042-08-06 Wed	67	—	unknown	23:00–23:20 (good, 0.33 h)	89.6° 05:05	6.13	67%	33.1°
2042-08-07 Thu	82	—	unknown	22:55–04:35 (good, 5.67 h)	89.8° 05:00	6.19	56%	33.4°
2042-08-08 Fri	85	—	unknown	22:50–04:35 (good, 5.75 h)	89.8° 04:55	6.25	44%	38.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-07-10&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.