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: 08-29 (100), 08-30 (100), 08-31 (100), 09-01 (100), 09-02 (100) — by astronomy; check the weather when the night is within four days.

2033-08-29astronomy score per night — click a bar for that night2033-09-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-08-29 Mon	100	—	unknown	21:40–05:10 (good, 7.5 h)	89.6° 03:30	7.46	21%	144.7°
2033-08-30 Tue	100	—	unknown	21:40–05:10 (good, 7.5 h)	89.5° 03:30	7.52	30%	141.0°
2033-08-31 Wed	100	—	unknown	21:35–05:10 (good, 7.58 h)	89.7° 03:25	7.57	39%	134.7°
2033-09-01 Thu	100	—	unknown	21:35–05:10 (good, 7.58 h)	89.8° 03:20	7.63	48%	126.6°
2033-09-02 Fri	100	—	unknown	21:35–05:15 (good, 7.67 h)	89.7° 03:15	7.68	58%	117.4°
2033-09-03 Sat	100	—	unknown	21:30–05:15 (good, 7.75 h)	89.6° 03:10	7.74	68%	107.2°
2033-09-04 Sun	100	—	unknown	21:30–05:15 (good, 7.75 h)	89.5° 03:10	7.79	78%	96.4°
2033-09-05 Mon	100	—	unknown	21:50–05:20 (good, 7.5 h)	89.7° 03:05	7.85	86%	85.1°
2033-09-06 Tue	100	—	unknown	23:30–05:20 (good, 5.83 h)	89.8° 03:00	7.9	93%	73.5°
2033-09-07 Wed	69	—	unknown	03:15–05:20 (good, 2.08 h)	89.7° 02:55	7.96	98%	62.0°
2033-09-08 Thu	57	—	unknown	21:20–05:20 (marginal, 8.0 h)	89.5° 02:50	8.01	100%	51.1°
2033-09-09 Fri	42	—	unknown	21:20–05:25 (marginal, 8.08 h)	89.6° 02:50	8.07	99%	41.9°
2033-09-10 Sat	42	—	unknown	21:15–05:25 (marginal, 8.17 h)	89.7° 02:45	8.12	95%	35.8°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-08-29&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.