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 (79), 07-16 (69), 07-03 (66), 07-04 (66), 07-02 (65) — by astronomy; check the weather when the night is within four days.

2036-06-18astronomy score per night — click a bar for that night2036-07-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-06-18 Wed	36	—	unknown	02:10–03:40 (good, 1.5 h)	89.7° 08:15	4.43	31%	38.6°
2036-06-19 Thu	40	—	unknown	02:05–03:40 (good, 1.58 h)	89.8° 08:10	4.42	22%	38.7°
2036-06-20 Fri	44	—	unknown	02:00–03:40 (good, 1.67 h)	89.7° 08:05	4.42	14%	42.5°
2036-06-21 Sat	46	—	unknown	02:00–03:40 (good, 1.67 h)	89.6° 08:00	4.42	7%	49.6°
2036-06-22 Sun	48	—	unknown	01:55–03:40 (good, 1.75 h)	89.6° 08:00	4.43	2%	58.8°
2036-06-23 Mon	50	—	unknown	01:50–03:40 (good, 1.83 h)	89.7° 07:55	4.43	0%	69.5°
2036-06-24 Tue	51	—	unknown	01:45–03:40 (good, 1.92 h)	89.8° 07:50	4.44	1%	81.0°
2036-06-25 Wed	53	—	unknown	01:40–03:40 (good, 2.0 h)	89.7° 07:45	4.45	5%	92.8°
2036-06-26 Thu	55	—	unknown	01:40–03:40 (good, 2.0 h)	89.5° 07:40	4.46	11%	104.5°
2036-06-27 Fri	57	—	unknown	01:35–03:40 (good, 2.08 h)	89.6° 07:40	4.48	20%	115.5°
2036-06-28 Sat	59	—	unknown	01:30–03:40 (good, 2.17 h)	89.7° 07:35	4.49	30%	125.5°
2036-06-29 Sun	61	—	unknown	01:25–03:45 (good, 2.33 h)	89.8° 07:30	4.51	41%	133.8°
2036-06-30 Mon	63	—	unknown	01:25–03:45 (good, 2.33 h)	89.6° 07:25	4.53	52%	139.5°
2036-07-01 Tue	64	—	unknown	01:25–03:45 (good, 2.33 h)	89.5° 07:25	4.55	63%	141.8°
2036-07-02 Wed	65	—	unknown	01:20–03:45 (good, 2.42 h)	89.7° 07:20	4.57	72%	140.3°
2036-07-03 Thu	66	—	unknown	01:20–03:45 (good, 2.42 h)	89.8° 07:15	4.6	81%	135.6°
2036-07-04 Fri	66	—	unknown	01:15–03:45 (good, 2.5 h)	89.7° 07:10	4.63	88%	128.7°
2036-07-05 Sat	62	—	unknown	01:15–03:50 (good, 2.58 h)	89.6° 07:05	4.65	94%	120.6°
2036-07-06 Sun	58	—	unknown	01:15–03:50 (good, 2.58 h)	89.6° 07:05	4.69	98%	111.8°
2036-07-07 Mon	52	—	unknown	01:20–03:50 (good, 2.5 h)	89.7° 07:00	4.72	100%	102.7°
2036-07-08 Tue	46	—	unknown	01:30–03:50 (good, 2.33 h)	89.8° 06:55	4.75	100%	93.3°
2036-07-09 Wed	42	—	unknown	02:15–03:55 (good, 1.67 h)	89.7° 06:50	4.79	98%	84.0°
2036-07-10 Thu	38	—	unknown	03:00–03:55 (good, 0.92 h)	89.5° 06:45	4.82	95%	74.8°
2036-07-11 Fri	35	—	unknown	03:40–03:55 (good, 0.25 h)	89.6° 06:45	4.86	90%	65.9°
2036-07-12 Sat	35	—	unknown	00:05–03:55 (marginal, 3.83 h)	89.7° 06:40	4.9	83%	57.5°
2036-07-13 Sun	37	—	unknown	03:50–04:00 (good, 0.17 h)	89.8° 06:35	4.94	75%	49.9°
2036-07-14 Mon	42	—	unknown	01:50–04:00 (good, 2.17 h)	89.6° 06:30	4.98	66%	43.6°
2036-07-15 Tue	56	—	unknown	00:25–04:00 (good, 3.58 h)	89.5° 06:30	5.02	57%	39.4°
2036-07-16 Wed	69	—	unknown	00:20–04:00 (good, 3.67 h)	89.7° 06:25	5.07	47%	38.4°
2036-07-17 Thu	79	—	unknown	00:15–04:05 (good, 3.83 h)	89.8° 06:20	5.11	36%	40.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-06-18&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.