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: 07-26 (100), 07-27 (100), 07-28 (100), 07-29 (100), 07-30 (100) — by astronomy; check the weather when the night is within four days.

2036-07-26astronomy score per night — click a bar for that night2036-08-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-07-26 Sat	100	—	unknown	23:40–04:15 (good, 4.58 h)	89.7° 05:45	5.56	17%	131.2°
2036-07-27 Sun	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.8° 05:40	5.61	27%	138.0°
2036-07-28 Mon	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.6° 05:35	5.66	37%	141.4°
2036-07-29 Tue	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.5° 05:35	5.72	48%	140.9°
2036-07-30 Wed	100	—	unknown	23:30–04:25 (good, 4.92 h)	89.7° 05:30	5.77	58%	136.8°
2036-07-31 Thu	100	—	unknown	23:30–04:25 (good, 4.92 h)	89.8° 05:25	5.82	68%	130.4°
2036-08-01 Fri	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.7° 05:20	5.88	77%	122.6°
2036-08-02 Sat	100	—	unknown	23:25–04:30 (good, 5.08 h)	89.6° 05:15	5.94	85%	114.0°
2036-08-03 Sun	100	—	unknown	23:30–04:30 (good, 5.0 h)	89.5° 05:15	5.99	91%	104.9°
2036-08-04 Mon	84	—	unknown	23:35–04:30 (good, 4.92 h)	89.7° 05:10	6.05	96%	95.7°
2036-08-05 Tue	77	—	unknown	00:15–04:35 (good, 4.33 h)	89.8° 05:05	6.1	99%	86.4°
2036-08-06 Wed	69	—	unknown	01:20–04:35 (good, 3.25 h)	89.7° 05:00	6.16	100%	77.1°
2036-08-07 Thu	57	—	unknown	03:20–04:35 (good, 1.25 h)	89.5° 04:55	6.22	99%	68.1°
2036-08-08 Fri	49	—	unknown	22:25–04:40 (marginal, 6.25 h)	89.6° 04:55	6.27	97%	59.6°
2036-08-09 Sat	43	—	unknown	22:20–04:40 (marginal, 6.33 h)	89.7° 04:50	6.33	93%	51.7°
2036-08-10 Sun	45	—	unknown	22:15–04:40 (marginal, 6.42 h)	89.8° 04:45	6.39	87%	45.1°
2036-08-11 Mon	61	—	unknown	22:40–22:50 (good, 0.17 h)	89.7° 04:40	6.45	80%	40.3°
2036-08-12 Tue	81	—	unknown	22:35–02:10 (good, 3.58 h)	89.5° 04:35	6.5	71%	38.3°
2036-08-13 Wed	85	—	unknown	22:30–04:45 (good, 6.25 h)	89.6° 04:35	6.56	62%	39.8°
2036-08-14 Thu	90	—	unknown	22:25–04:45 (good, 6.33 h)	89.8° 04:30	6.62	51%	44.5°
2036-08-15 Fri	95	—	unknown	22:20–04:50 (good, 6.5 h)	89.7° 04:25	6.68	41%	51.8°
2036-08-16 Sat	100	—	unknown	22:20–04:50 (good, 6.5 h)	89.6° 04:20	6.73	30%	60.9°
2036-08-17 Sun	100	—	unknown	22:15–04:50 (good, 6.58 h)	89.5° 04:20	6.79	20%	71.3°
2036-08-18 Mon	100	—	unknown	22:10–04:55 (good, 6.75 h)	89.7° 04:15	6.85	11%	82.5°
2036-08-19 Tue	100	—	unknown	22:05–04:55 (good, 6.83 h)	89.8° 04:10	6.91	5%	94.3°
2036-08-20 Wed	100	—	unknown	22:00–04:55 (good, 6.92 h)	89.7° 04:05	6.96	1%	106.0°
2036-08-21 Thu	100	—	unknown	22:00–04:55 (good, 6.92 h)	89.6° 04:00	7.02	0%	117.3°
2036-08-22 Fri	100	—	unknown	21:55–05:00 (good, 7.08 h)	89.6° 04:00	7.08	2%	127.5°
2036-08-23 Sat	100	—	unknown	21:50–05:00 (good, 7.17 h)	89.7° 03:55	7.13	7%	135.6°
2036-08-24 Sun	100	—	unknown	21:50–05:00 (good, 7.17 h)	89.8° 03:50	7.19	14%	140.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-07-26&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.