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: 07-11 (85), 07-12 (85), 07-13 (85), 07-10 (84), 07-09 (81) — by astronomy; check the weather when the night is within four days.

2038-06-19astronomy score per night — click a bar for that night2038-07-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-06-19 Sat	23	—	unknown	02:50–03:40 (good, 0.83 h)	89.6° 08:10	4.42	90%	85.0°
2038-06-20 Sun	23	—	unknown	03:05–03:40 (good, 0.58 h)	89.5° 08:10	4.42	83%	74.8°
2038-06-21 Mon	23	—	unknown	03:00–03:40 (good, 0.67 h)	89.7° 08:05	4.42	74%	65.2°
2038-06-22 Tue	25	—	unknown	02:25–03:40 (good, 1.25 h)	89.8° 08:00	4.43	65%	56.5°
2038-06-23 Wed	28	—	unknown	02:15–03:40 (good, 1.42 h)	89.7° 07:55	4.43	56%	48.9°
2038-06-24 Thu	33	—	unknown	02:05–03:40 (good, 1.58 h)	89.5° 07:50	4.44	46%	43.0°
2038-06-25 Fri	42	—	unknown	01:45–03:40 (good, 1.92 h)	89.6° 07:50	4.45	37%	39.3°
2038-06-26 Sat	48	—	unknown	01:40–03:40 (good, 2.0 h)	89.7° 07:45	4.46	28%	38.4°
2038-06-27 Sun	52	—	unknown	01:35–03:40 (good, 2.08 h)	89.8° 07:40	4.47	20%	40.6°
2038-06-28 Mon	57	—	unknown	01:35–03:40 (good, 2.08 h)	89.7° 07:35	4.48	13%	45.5°
2038-06-29 Tue	59	—	unknown	01:30–03:40 (good, 2.17 h)	89.5° 07:30	4.5	7%	52.3°
2038-06-30 Wed	63	—	unknown	01:25–03:45 (good, 2.33 h)	89.7° 07:30	4.52	3%	60.5°
2038-07-01 Thu	64	—	unknown	01:20–03:45 (good, 2.42 h)	89.8° 07:25	4.54	0%	69.6°
2038-07-02 Fri	66	—	unknown	01:15–03:45 (good, 2.5 h)	89.8° 07:20	4.56	0%	79.5°
2038-07-03 Sat	68	—	unknown	01:15–03:45 (good, 2.5 h)	89.6° 07:15	4.59	2%	89.7°
2038-07-04 Sun	70	—	unknown	01:10–03:45 (good, 2.58 h)	89.5° 07:15	4.61	6%	100.1°
2038-07-05 Mon	74	—	unknown	01:05–03:50 (good, 2.75 h)	89.7° 07:10	4.64	13%	110.5°
2038-07-06 Tue	75	—	unknown	01:00–03:50 (good, 2.83 h)	89.8° 07:05	4.67	21%	120.4°
2038-07-07 Wed	77	—	unknown	00:55–03:50 (good, 2.92 h)	89.7° 07:00	4.7	31%	129.5°
2038-07-08 Thu	79	—	unknown	00:55–03:50 (good, 2.92 h)	89.6° 06:55	4.73	42%	136.7°
2038-07-09 Fri	81	—	unknown	00:55–03:50 (good, 2.92 h)	89.6° 06:55	4.77	53%	141.0°
2038-07-10 Sat	84	—	unknown	00:50–03:55 (good, 3.08 h)	89.7° 06:50	4.8	64%	141.2°
2038-07-11 Sun	85	—	unknown	00:50–03:55 (good, 3.08 h)	89.8° 06:45	4.84	75%	137.1°
2038-07-12 Mon	85	—	unknown	00:45–03:55 (good, 3.17 h)	89.7° 06:40	4.88	84%	129.9°
2038-07-13 Tue	85	—	unknown	00:45–03:55 (good, 3.17 h)	89.5° 06:35	4.92	92%	120.7°
2038-07-14 Wed	73	—	unknown	00:45–04:00 (good, 3.25 h)	89.6° 06:35	4.96	97%	110.5°
2038-07-15 Thu	63	—	unknown	00:50–04:00 (good, 3.17 h)	89.8° 06:30	5.0	100%	99.8°
2038-07-16 Fri	55	—	unknown	01:10–04:00 (good, 2.83 h)	89.8° 06:25	5.05	100%	89.1°
2038-07-17 Sat	48	—	unknown	02:05–04:05 (good, 2.0 h)	89.6° 06:20	5.09	98%	78.7°
2038-07-18 Sun	42	—	unknown	03:00–04:05 (good, 1.08 h)	89.5° 06:20	5.14	93%	68.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-06-19&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.