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: 01-17 (100), 01-18 (100), 01-19 (100), 01-20 (100), 01-21 (100) — by astronomy; check the weather when the night is within four days.

2033-01-09astronomy score per night — click a bar for that night2033-02-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-01-09 Sun	37	—	unknown	18:50–00:15 (marginal, 5.42 h)	89.5° 17:50	11.34	69%	37.4°
2033-01-10 Mon	32	—	unknown	18:50–00:00 (marginal, 5.17 h)	89.7° 17:45	11.32	79%	44.6°
2033-01-11 Tue	32	—	unknown	18:55–23:50 (marginal, 4.92 h)	89.8° 17:40	11.3	87%	53.7°
2033-01-12 Wed	37	—	unknown	18:55–23:45 (marginal, 4.83 h)	89.7° 17:35	11.28	93%	63.7°
2033-01-13 Thu	46	—	unknown	18:55–19:55 (good, 1.0 h)	89.6° 17:30	11.26	97%	74.1°
2033-01-14 Fri	57	—	unknown	18:55–21:10 (good, 2.25 h)	89.5° 17:30	11.24	99%	84.6°
2033-01-15 Sat	70	—	unknown	18:55–22:15 (good, 3.33 h)	89.7° 17:25	11.22	100%	95.0°
2033-01-16 Sun	84	—	unknown	18:55–23:00 (good, 4.08 h)	89.8° 17:20	11.2	98%	105.2°
2033-01-17 Mon	100	—	unknown	19:00–23:10 (good, 4.17 h)	89.7° 17:15	11.17	94%	115.0°
2033-01-18 Tue	100	—	unknown	19:00–23:10 (good, 4.17 h)	89.5° 17:10	11.15	89%	124.2°
2033-01-19 Wed	100	—	unknown	19:00–23:10 (good, 4.17 h)	89.6° 17:10	11.12	83%	132.6°
2033-01-20 Thu	100	—	unknown	19:00–23:05 (good, 4.08 h)	89.7° 17:05	11.1	75%	139.7°
2033-01-21 Fri	100	—	unknown	19:05–23:10 (good, 4.08 h)	89.7° 17:00	11.07	67%	144.7°
2033-01-22 Sat	100	—	unknown	19:05–23:05 (good, 4.0 h)	89.6° 16:55	11.05	58%	146.6°
2033-01-23 Sun	100	—	unknown	19:05–23:00 (good, 3.92 h)	89.5° 16:55	11.02	48%	144.7°
2033-01-24 Mon	100	—	unknown	19:05–22:55 (good, 3.83 h)	89.6° 16:50	10.99	38%	139.5°
2033-01-25 Tue	99	—	unknown	19:05–22:55 (good, 3.83 h)	89.8° 16:45	10.96	29%	131.7°
2033-01-26 Wed	97	—	unknown	19:10–22:50 (good, 3.67 h)	89.7° 16:40	10.93	20%	122.3°
2033-01-27 Thu	95	—	unknown	19:10–22:45 (good, 3.58 h)	89.6° 16:35	10.91	12%	111.6°
2033-01-28 Fri	93	—	unknown	19:10–22:40 (good, 3.5 h)	89.5° 16:35	10.87	6%	100.1°
2033-01-29 Sat	90	—	unknown	19:10–22:40 (good, 3.5 h)	89.7° 16:30	10.84	2%	88.1°
2033-01-30 Sun	88	—	unknown	19:10–22:35 (good, 3.42 h)	89.8° 16:25	10.81	0%	75.8°
2033-01-31 Mon	85	—	unknown	19:15–22:30 (good, 3.25 h)	89.7° 16:20	10.78	2%	63.7°
2033-02-01 Tue	81	—	unknown	19:15–22:25 (good, 3.17 h)	89.5° 16:15	10.75	6%	52.4°
2033-02-02 Wed	73	—	unknown	19:15–22:20 (good, 3.08 h)	89.6° 16:15	10.71	13%	42.6°
2033-02-03 Thu	61	—	unknown	19:15–22:10 (good, 2.92 h)	89.7° 16:10	10.68	22%	35.8°
2033-02-04 Fri	48	—	unknown	19:20–21:55 (good, 2.58 h)	89.7° 16:05	10.65	32%	33.6°
2033-02-05 Sat	38	—	unknown	19:20–21:40 (good, 2.33 h)	89.6° 16:00	10.61	43%	36.4°
2033-02-06 Sun	30	—	unknown	19:20–19:40 (good, 0.33 h)	89.5° 16:00	10.58	54%	43.1°
2033-02-07 Mon	25	—	unknown	19:20–22:25 (marginal, 3.08 h)	89.6° 15:55	10.54	65%	51.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-01-09&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.