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: 09-15 (100), 09-16 (100), 09-17 (100), 09-18 (100), 09-19 (100) — by astronomy; check the weather when the night is within four days.

2033-09-11astronomy score per night — click a bar for that night2033-10-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-09-11 Sun	53	—	unknown	20:40–05:25 (marginal, 8.75 h)	89.7° 02:40	8.18	88%	34.9°
2033-09-12 Mon	85	—	unknown	21:15–23:35 (good, 2.33 h)	89.6° 02:35	8.23	80%	39.2°
2033-09-13 Tue	91	—	unknown	21:10–02:45 (good, 5.58 h)	89.5° 02:35	8.28	70%	47.0°
2033-09-14 Wed	97	—	unknown	21:10–05:30 (good, 8.33 h)	89.6° 02:30	8.34	59%	56.5°
2033-09-15 Thu	100	—	unknown	21:05–05:30 (good, 8.42 h)	89.8° 02:25	8.39	48%	66.9°
2033-09-16 Fri	100	—	unknown	21:05–05:30 (good, 8.42 h)	89.7° 02:20	8.44	37%	77.4°
2033-09-17 Sat	100	—	unknown	21:05–05:35 (good, 8.5 h)	89.6° 02:15	8.49	28%	88.0°
2033-09-18 Sun	100	—	unknown	21:00–05:35 (good, 8.58 h)	89.5° 02:15	8.54	19%	98.3°
2033-09-19 Mon	100	—	unknown	21:00–05:35 (good, 8.58 h)	89.7° 02:10	8.6	12%	108.4°
2033-09-20 Tue	100	—	unknown	21:00–05:35 (good, 8.58 h)	89.8° 02:05	8.65	6%	118.0°
2033-09-21 Wed	100	—	unknown	20:55–05:40 (good, 8.75 h)	89.7° 02:00	8.7	2%	126.9°
2033-09-22 Thu	100	—	unknown	20:55–05:40 (good, 8.75 h)	89.5° 01:55	8.75	0%	134.7°
2033-09-23 Fri	100	—	unknown	20:50–05:40 (good, 8.83 h)	89.6° 01:55	8.8	0%	140.9°
2033-09-24 Sat	100	—	unknown	20:50–05:40 (good, 8.83 h)	89.7° 01:50	8.85	2%	144.7°
2033-09-25 Sun	100	—	unknown	20:50–05:40 (good, 8.83 h)	89.7° 01:45	8.9	5%	145.1°
2033-09-26 Mon	100	—	unknown	20:45–05:45 (good, 9.0 h)	89.6° 01:40	8.95	10%	142.2°
2033-09-27 Tue	100	—	unknown	20:45–05:45 (good, 9.0 h)	89.5° 01:40	9.0	16%	136.6°
2033-09-28 Wed	100	—	unknown	20:45–05:45 (good, 9.0 h)	89.6° 01:35	9.05	24%	129.0°
2033-09-29 Thu	100	—	unknown	20:40–05:45 (good, 9.08 h)	89.8° 01:30	9.1	32%	120.2°
2033-09-30 Fri	100	—	unknown	20:40–05:50 (good, 9.17 h)	89.7° 01:25	9.15	42%	110.6°
2033-10-01 Sat	100	—	unknown	20:35–05:50 (good, 9.25 h)	89.6° 01:20	9.19	52%	100.3°
2033-10-02 Sun	100	—	unknown	20:35–05:50 (good, 9.25 h)	89.5° 01:20	9.24	63%	89.5°
2033-10-03 Mon	100	—	unknown	20:35–05:50 (good, 9.25 h)	89.7° 01:15	9.29	73%	78.3°
2033-10-04 Tue	100	—	unknown	21:30–05:50 (good, 8.33 h)	89.8° 01:10	9.34	83%	67.0°
2033-10-05 Wed	94	—	unknown	02:00–05:55 (good, 3.92 h)	89.7° 01:05	9.38	91%	56.0°
2033-10-06 Thu	85	—	unknown	05:50–05:55 (good, 0.08 h)	89.5° 01:00	9.43	96%	45.9°
2033-10-07 Fri	46	—	unknown	20:25–05:55 (marginal, 9.5 h)	89.6° 01:00	9.48	100%	38.1°
2033-10-08 Sat	41	—	unknown	20:25–05:55 (marginal, 9.5 h)	89.7° 00:55	9.52	100%	34.6°
2033-10-09 Sun	51	—	unknown	20:25–06:00 (marginal, 9.58 h)	89.8° 00:50	9.57	97%	36.8°
2033-10-10 Mon	88	—	unknown	20:20–20:45 (good, 0.42 h)	89.6° 00:45	9.61	91%	43.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-09-11&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.