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: 07-10 (84), 07-11 (83), 07-09 (81), 07-08 (79), 07-07 (77) — by astronomy; check the weather when the night is within four days.

2030-06-21astronomy score per night — click a bar for that night2030-07-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-06-21 Fri	23	—	unknown	03:25–03:40 (good, 0.25 h)	89.6° 08:05	4.42	58%	44.0°
2030-06-22 Sat	26	—	unknown	02:25–03:40 (good, 1.25 h)	89.7° 08:00	4.42	48%	36.0°
2030-06-23 Sun	31	—	unknown	02:10–03:40 (good, 1.5 h)	89.7° 07:55	4.43	38%	30.7°
2030-06-24 Mon	38	—	unknown	01:50–03:40 (good, 1.83 h)	89.6° 07:50	4.44	29%	29.4°
2030-06-25 Tue	45	—	unknown	01:45–03:40 (good, 1.92 h)	89.5° 07:50	4.44	21%	32.4°
2030-06-26 Wed	51	—	unknown	01:40–03:40 (good, 2.0 h)	89.7° 07:45	4.46	14%	38.5°
2030-06-27 Thu	55	—	unknown	01:35–03:40 (good, 2.08 h)	89.7° 07:40	4.47	8%	46.6°
2030-06-28 Fri	58	—	unknown	01:35–03:40 (good, 2.08 h)	89.7° 07:35	4.48	4%	55.8°
2030-06-29 Sat	59	—	unknown	01:30–03:40 (good, 2.17 h)	89.5° 07:30	4.5	1%	65.7°
2030-06-30 Sun	63	—	unknown	01:25–03:45 (good, 2.33 h)	89.6° 07:30	4.52	0%	76.0°
2030-07-01 Mon	64	—	unknown	01:20–03:45 (good, 2.42 h)	89.7° 07:25	4.54	1%	86.6°
2030-07-02 Tue	66	—	unknown	01:15–03:45 (good, 2.5 h)	89.7° 07:20	4.56	4%	97.3°
2030-07-03 Wed	68	—	unknown	01:15–03:45 (good, 2.5 h)	89.6° 07:15	4.58	9%	108.1°
2030-07-04 Thu	70	—	unknown	01:10–03:45 (good, 2.58 h)	89.5° 07:15	4.61	16%	118.9°
2030-07-05 Fri	74	—	unknown	01:05–03:50 (good, 2.75 h)	89.6° 07:10	4.64	24%	129.3°
2030-07-06 Sat	75	—	unknown	01:00–03:50 (good, 2.83 h)	89.7° 07:05	4.67	34%	138.9°
2030-07-07 Sun	77	—	unknown	00:55–03:50 (good, 2.92 h)	89.7° 07:00	4.7	44%	146.6°
2030-07-08 Mon	79	—	unknown	00:55–03:50 (good, 2.92 h)	89.6° 06:55	4.73	55%	150.5°
2030-07-09 Tue	81	—	unknown	00:55–03:50 (good, 2.92 h)	89.5° 06:55	4.77	66%	148.7°
2030-07-10 Wed	84	—	unknown	00:55–03:55 (good, 3.0 h)	89.7° 06:50	4.8	77%	141.8°
2030-07-11 Thu	83	—	unknown	00:50–03:55 (good, 3.08 h)	89.7° 06:45	4.84	86%	131.7°
2030-07-12 Fri	76	—	unknown	00:50–03:55 (good, 3.08 h)	89.7° 06:40	4.88	93%	119.9°
2030-07-13 Sat	67	—	unknown	00:55–03:55 (good, 3.0 h)	89.5° 06:35	4.92	98%	107.4°
2030-07-14 Sun	56	—	unknown	01:00–04:00 (good, 3.0 h)	89.6° 06:35	4.96	100%	94.6°
2030-07-15 Mon	46	—	unknown	02:20–04:00 (good, 1.67 h)	89.7° 06:30	5.0	99%	81.9°
2030-07-16 Tue	37	—	unknown	03:40–04:00 (good, 0.33 h)	89.7° 06:25	5.04	95%	69.6°
2030-07-17 Wed	33	—	unknown	23:55–04:05 (marginal, 4.17 h)	89.6° 06:20	5.09	89%	58.1°
2030-07-18 Thu	31	—	unknown	23:50–04:05 (marginal, 4.25 h)	89.5° 06:20	5.13	82%	47.5°
2030-07-19 Fri	34	—	unknown	23:40–04:05 (marginal, 4.42 h)	89.6° 06:15	5.18	73%	38.6°
2030-07-20 Sat	40	—	unknown	23:35–04:05 (marginal, 4.5 h)	89.7° 06:10	5.23	64%	32.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-06-21&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.