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: 06-19 (42), 06-18 (41), 06-17 (39), 06-16 (38), 06-15 (37) — by astronomy; check the weather when the night is within four days.

2034-05-21astronomy score per night — click a bar for that night2034-06-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-05-21 Sun	9	—	unknown	03:30–04:45 (marginal, 1.25 h)	89.7° 10:05	5.27	20%	88.7°
2034-05-22 Mon	9	—	unknown	04:00–04:45 (marginal, 0.75 h)	89.6° 10:00	5.22	29%	99.9°
2034-05-23 Tue	10	—	unknown	03:20–04:45 (marginal, 1.42 h)	89.5° 10:00	5.17	39%	110.4°
2034-05-24 Wed	11	—	unknown	03:50–03:55 (good, 0.08 h)	89.7° 09:55	5.13	49%	120.2°
2034-05-25 Thu	12	—	unknown	03:45–03:55 (good, 0.17 h)	89.8° 09:50	5.08	59%	129.0°
2034-05-26 Fri	12	—	unknown	03:40–03:50 (good, 0.17 h)	89.7° 09:45	5.04	69%	136.4°
2034-05-27 Sat	13	—	unknown	03:40–03:50 (good, 0.17 h)	89.5° 09:40	4.99	77%	141.8°
2034-05-28 Sun	13	—	unknown	03:40–03:50 (good, 0.17 h)	89.6° 09:40	4.95	85%	144.4°
2034-05-29 Mon	14	—	unknown	03:40–03:50 (good, 0.17 h)	89.7° 09:35	4.91	91%	143.6°
2034-05-30 Tue	13	—	unknown	03:35–03:45 (good, 0.17 h)	89.8° 09:30	4.87	95%	139.7°
2034-05-31 Wed	14	—	unknown	03:35–03:45 (good, 0.17 h)	89.6° 09:25	4.83	98%	133.5°
2034-06-01 Thu	15	—	unknown	03:30–03:45 (good, 0.25 h)	89.5° 09:20	4.79	100%	125.7°
2034-06-02 Fri	16	—	unknown	03:30–03:45 (good, 0.25 h)	89.6° 09:20	4.76	99%	116.9°
2034-06-03 Sat	15	—	unknown	03:30–03:45 (good, 0.25 h)	89.8° 09:15	4.72	97%	107.4°
2034-06-04 Sun	14	—	unknown	03:35–03:45 (good, 0.17 h)	89.7° 09:10	4.69	93%	97.5°
2034-06-05 Mon	13	—	unknown	02:30–04:35 (marginal, 2.08 h)	89.6° 09:05	4.66	87%	87.3°
2034-06-06 Tue	13	—	unknown	02:25–03:40 (marginal, 1.25 h)	89.5° 09:05	4.63	79%	77.1°
2034-06-07 Wed	14	—	unknown	02:20–03:40 (marginal, 1.33 h)	89.7° 09:00	4.61	70%	66.8°
2034-06-08 Thu	15	—	unknown	03:20–03:40 (good, 0.33 h)	89.8° 08:55	4.58	60%	56.9°
2034-06-09 Fri	17	—	unknown	03:10–03:40 (good, 0.5 h)	89.7° 08:50	4.56	49%	47.8°
2034-06-10 Sat	21	—	unknown	03:00–03:40 (good, 0.67 h)	89.5° 08:45	4.53	38%	40.4°
2034-06-11 Sun	26	—	unknown	02:40–03:40 (good, 1.0 h)	89.6° 08:45	4.51	27%	36.1°
2034-06-12 Mon	32	—	unknown	02:35–03:40 (good, 1.08 h)	89.7° 08:40	4.5	17%	36.5°
2034-06-13 Tue	33	—	unknown	02:30–03:40 (good, 1.17 h)	89.8° 08:35	4.48	9%	41.7°
2034-06-14 Wed	35	—	unknown	02:30–03:40 (good, 1.17 h)	89.7° 08:30	4.47	4%	50.3°
2034-06-15 Thu	37	—	unknown	02:25–03:40 (good, 1.25 h)	89.5° 08:25	4.45	1%	60.8°
2034-06-16 Fri	38	—	unknown	02:20–03:40 (good, 1.33 h)	89.6° 08:25	4.44	0%	72.2°
2034-06-17 Sat	39	—	unknown	02:15–03:40 (good, 1.42 h)	89.7° 08:20	4.43	3%	83.9°
2034-06-18 Sun	41	—	unknown	02:10–03:40 (good, 1.5 h)	89.7° 08:15	4.43	9%	95.4°
2034-06-19 Mon	42	—	unknown	02:10–03:40 (good, 1.5 h)	89.6° 08:10	4.42	16%	106.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-05-21&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.