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: 07-31 (100), 08-01 (100), 08-02 (100), 07-30 (99), 07-29 (93) — by astronomy; check the weather when the night is within four days.

2035-07-04astronomy score per night — click a bar for that night2035-08-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-07-04 Wed	70	—	unknown	01:10–03:45 (good, 2.58 h)	89.7° 07:15	4.61	0%	74.4°
2035-07-05 Thu	71	—	unknown	01:05–03:45 (good, 2.67 h)	89.8° 07:10	4.63	0%	86.4°
2035-07-06 Fri	75	—	unknown	01:00–03:50 (good, 2.83 h)	89.7° 07:05	4.66	4%	98.3°
2035-07-07 Sat	77	—	unknown	01:00–03:50 (good, 2.83 h)	89.6° 07:00	4.69	9%	109.8°
2035-07-08 Sun	79	—	unknown	00:55–03:50 (good, 2.92 h)	89.6° 07:00	4.73	17%	120.4°
2035-07-09 Mon	81	—	unknown	00:50–03:50 (good, 3.0 h)	89.7° 06:55	4.76	26%	129.6°
2035-07-10 Tue	85	—	unknown	00:45–03:55 (good, 3.17 h)	89.8° 06:50	4.79	36%	136.9°
2035-07-11 Wed	87	—	unknown	00:45–03:55 (good, 3.17 h)	89.7° 06:45	4.83	46%	141.5°
2035-07-12 Thu	88	—	unknown	00:45–03:55 (good, 3.17 h)	89.5° 06:40	4.87	56%	142.6°
2035-07-13 Fri	90	—	unknown	00:40–03:55 (good, 3.25 h)	89.6° 06:40	4.91	66%	140.4°
2035-07-14 Sat	92	—	unknown	00:40–04:00 (good, 3.33 h)	89.7° 06:35	4.95	75%	135.4°
2035-07-15 Sun	92	—	unknown	00:35–04:00 (good, 3.42 h)	89.8° 06:30	4.99	82%	128.5°
2035-07-16 Mon	92	—	unknown	00:35–04:00 (good, 3.42 h)	89.6° 06:25	5.03	89%	120.6°
2035-07-17 Tue	79	—	unknown	00:35–04:00 (good, 3.42 h)	89.5° 06:25	5.08	94%	111.9°
2035-07-18 Wed	71	—	unknown	00:40–04:05 (good, 3.42 h)	89.7° 06:20	5.12	98%	102.7°
2035-07-19 Thu	61	—	unknown	00:50–04:05 (good, 3.25 h)	89.8° 06:15	5.17	100%	93.3°
2035-07-20 Fri	53	—	unknown	01:45–04:05 (good, 2.33 h)	89.7° 06:10	5.22	100%	83.8°
2035-07-21 Sat	46	—	unknown	02:45–04:10 (good, 1.42 h)	89.6° 06:05	5.26	98%	74.2°
2035-07-22 Sun	40	—	unknown	23:35–04:10 (marginal, 4.58 h)	89.6° 06:05	5.31	94%	64.9°
2035-07-23 Mon	38	—	unknown	23:30–04:10 (marginal, 4.67 h)	89.7° 06:00	5.36	89%	56.0°
2035-07-24 Tue	39	—	unknown	23:20–04:15 (marginal, 4.92 h)	89.8° 05:55	5.41	82%	48.0°
2035-07-25 Wed	44	—	unknown	23:15–04:15 (marginal, 5.0 h)	89.7° 05:50	5.46	73%	41.6°
2035-07-26 Thu	64	—	unknown	00:15–04:15 (good, 4.0 h)	89.5° 05:45	5.52	63%	37.9°
2035-07-27 Fri	81	—	unknown	23:40–04:15 (good, 4.58 h)	89.6° 05:45	5.57	52%	38.0°
2035-07-28 Sat	88	—	unknown	23:35–04:20 (good, 4.75 h)	89.7° 05:40	5.62	41%	42.0°
2035-07-29 Sun	93	—	unknown	23:30–04:20 (good, 4.83 h)	89.8° 05:35	5.67	30%	49.4°
2035-07-30 Mon	99	—	unknown	23:30–04:20 (good, 4.83 h)	89.6° 05:30	5.73	20%	58.9°
2035-07-31 Tue	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.5° 05:30	5.78	11%	69.7°
2035-08-01 Wed	100	—	unknown	23:20–04:25 (good, 5.08 h)	89.7° 05:25	5.84	5%	81.3°
2035-08-02 Thu	100	—	unknown	23:15–04:25 (good, 5.17 h)	89.8° 05:20	5.89	1%	93.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-07-04&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.