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: 06-15 (35), 06-14 (34), 06-13 (33), 06-16 (33), 06-17 (33) — by astronomy; check the weather when the night is within four days.

2035-05-26astronomy score per night — click a bar for that night2035-06-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-05-26 Sat	7	—	unknown	03:10–03:50 (marginal, 0.67 h)	89.5° 09:45	5.05	81%	88.5°
2035-05-27 Sun	8	—	unknown	03:05–03:50 (marginal, 0.75 h)	89.6° 09:45	5.0	73%	78.9°
2035-05-28 Mon	9	—	unknown	03:00–03:50 (marginal, 0.83 h)	89.7° 09:40	4.96	64%	69.4°
2035-05-29 Tue	10	—	unknown	03:00–03:50 (marginal, 0.83 h)	89.8° 09:35	4.92	54%	60.2°
2035-05-30 Wed	11	—	unknown	02:55–03:45 (marginal, 0.83 h)	89.7° 09:30	4.88	44%	51.5°
2035-05-31 Thu	13	—	unknown	03:40–03:45 (good, 0.08 h)	89.5° 09:25	4.84	33%	43.9°
2035-06-01 Fri	16	—	unknown	03:20–03:45 (good, 0.42 h)	89.6° 09:25	4.8	24%	38.6°
2035-06-02 Sat	19	—	unknown	03:15–03:45 (good, 0.5 h)	89.8° 09:20	4.77	15%	37.1°
2035-06-03 Sun	22	—	unknown	03:10–03:45 (good, 0.58 h)	89.7° 09:15	4.73	7%	40.1°
2035-06-04 Mon	23	—	unknown	03:10–03:45 (good, 0.58 h)	89.6° 09:10	4.7	2%	47.1°
2035-06-05 Tue	24	—	unknown	03:05–03:40 (good, 0.58 h)	89.5° 09:10	4.67	0%	56.8°
2035-06-06 Wed	25	—	unknown	03:00–03:40 (good, 0.67 h)	89.7° 09:05	4.64	1%	67.9°
2035-06-07 Thu	25	—	unknown	02:55–03:40 (good, 0.75 h)	89.8° 09:00	4.61	5%	79.7°
2035-06-08 Fri	27	—	unknown	02:50–03:40 (good, 0.83 h)	89.7° 08:55	4.59	12%	91.6°
2035-06-09 Sat	28	—	unknown	02:50–03:40 (good, 0.83 h)	89.6° 08:50	4.56	20%	103.1°
2035-06-10 Sun	30	—	unknown	02:45–03:40 (good, 0.92 h)	89.6° 08:50	4.54	30%	114.0°
2035-06-11 Mon	31	—	unknown	02:40–03:40 (good, 1.0 h)	89.7° 08:45	4.52	40%	123.9°
2035-06-12 Tue	32	—	unknown	02:35–03:40 (good, 1.08 h)	89.8° 08:40	4.5	51%	132.4°
2035-06-13 Wed	33	—	unknown	02:35–03:40 (good, 1.08 h)	89.7° 08:35	4.48	61%	138.8°
2035-06-14 Thu	34	—	unknown	02:35–03:40 (good, 1.08 h)	89.5° 08:30	4.47	71%	142.4°
2035-06-15 Fri	35	—	unknown	02:30–03:40 (good, 1.17 h)	89.6° 08:30	4.46	79%	142.6°
2035-06-16 Sat	33	—	unknown	02:30–03:40 (good, 1.17 h)	89.8° 08:25	4.44	87%	139.5°
2035-06-17 Sun	33	—	unknown	02:25–03:40 (good, 1.25 h)	89.7° 08:20	4.44	92%	133.9°
2035-06-18 Mon	33	—	unknown	02:25–03:40 (good, 1.25 h)	89.6° 08:15	4.43	97%	126.7°
2035-06-19 Tue	33	—	unknown	02:20–03:40 (good, 1.33 h)	89.5° 08:15	4.43	99%	118.5°
2035-06-20 Wed	31	—	unknown	02:25–03:40 (good, 1.25 h)	89.7° 08:10	4.42	100%	109.6°
2035-06-21 Thu	28	—	unknown	02:30–03:40 (good, 1.17 h)	89.8° 08:05	4.42	99%	100.4°
2035-06-22 Fri	25	—	unknown	02:40–03:40 (good, 1.0 h)	89.7° 08:00	4.42	96%	90.9°
2035-06-23 Sat	24	—	unknown	03:15–03:40 (good, 0.42 h)	89.6° 07:55	4.43	91%	81.4°
2035-06-24 Sun	23	—	unknown	01:20–03:40 (marginal, 2.33 h)	89.6° 07:55	4.43	85%	71.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-05-26&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.