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: 12-13 (100), 12-14 (100), 12-15 (100), 12-16 (100), 12-17 (100) — by astronomy; check the weather when the night is within four days.

2033-12-13astronomy score per night — click a bar for that night2034-01-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-12-13 Tue	100	—	unknown	18:35–01:40 (good, 7.08 h)	89.8° 19:35	11.48	47%	135.7°
2033-12-14 Wed	100	—	unknown	18:35–01:35 (good, 7.0 h)	89.7° 19:30	11.49	38%	141.6°
2033-12-15 Thu	100	—	unknown	18:35–01:35 (good, 7.0 h)	89.6° 19:25	11.49	29%	144.8°
2033-12-16 Fri	100	—	unknown	18:35–01:30 (good, 6.92 h)	89.6° 19:25	11.5	21%	144.7°
2033-12-17 Sat	100	—	unknown	18:35–01:30 (good, 6.92 h)	89.7° 19:20	11.5	14%	141.3°
2033-12-18 Sun	100	—	unknown	18:35–01:25 (good, 6.83 h)	89.8° 19:15	11.5	8%	135.2°
2033-12-19 Mon	100	—	unknown	18:35–01:20 (good, 6.75 h)	89.7° 19:10	11.51	4%	127.3°
2033-12-20 Tue	100	—	unknown	18:35–01:15 (good, 6.67 h)	89.5° 19:05	11.51	1%	118.2°
2033-12-21 Wed	100	—	unknown	18:35–01:10 (good, 6.58 h)	89.6° 19:05	11.51	0%	108.3°
2033-12-22 Thu	100	—	unknown	18:35–01:10 (good, 6.58 h)	89.7° 19:00	11.51	2%	97.9°
2033-12-23 Fri	100	—	unknown	18:40–01:05 (good, 6.42 h)	89.7° 18:55	11.5	5%	87.1°
2033-12-24 Sat	100	—	unknown	18:40–01:00 (good, 6.33 h)	89.6° 18:50	11.5	11%	76.3°
2033-12-25 Sun	100	—	unknown	18:40–00:55 (good, 6.25 h)	89.5° 18:50	11.5	18%	65.5°
2033-12-26 Mon	95	—	unknown	18:40–00:50 (good, 6.17 h)	89.7° 18:45	11.49	28%	55.3°
2033-12-27 Tue	87	—	unknown	18:40–00:50 (good, 6.17 h)	89.8° 18:40	11.49	38%	46.1°
2033-12-28 Wed	74	—	unknown	18:40–00:45 (good, 6.08 h)	89.7° 18:35	11.48	49%	38.9°
2033-12-29 Thu	60	—	unknown	20:40–22:00 (good, 1.33 h)	89.6° 18:30	11.48	60%	35.2°
2033-12-30 Fri	42	—	unknown	18:40–01:00 (marginal, 6.33 h)	89.5° 18:30	11.47	71%	36.2°
2033-12-31 Sat	34	—	unknown	18:45–00:40 (marginal, 5.92 h)	89.7° 18:25	11.46	81%	41.8°
2034-01-01 Sun	34	—	unknown	18:45–00:30 (marginal, 5.75 h)	89.8° 18:20	11.45	89%	50.4°
2034-01-02 Mon	41	—	unknown	18:45–00:25 (marginal, 5.67 h)	89.7° 18:15	11.44	95%	60.6°
2034-01-03 Tue	53	—	unknown	18:45–19:45 (good, 1.0 h)	89.5° 18:10	11.43	99%	71.6°
2034-01-04 Wed	68	—	unknown	18:45–21:40 (good, 2.92 h)	89.6° 18:10	11.41	100%	82.9°
2034-01-05 Thu	82	—	unknown	18:45–22:55 (good, 4.17 h)	89.7° 18:05	11.4	98%	94.1°
2034-01-06 Fri	100	—	unknown	18:50–23:45 (good, 4.92 h)	89.7° 18:00	11.39	95%	105.0°
2034-01-07 Sat	100	—	unknown	18:50–23:50 (good, 5.0 h)	89.6° 17:55	11.37	89%	115.3°
2034-01-08 Sun	100	—	unknown	18:50–23:50 (good, 5.0 h)	89.5° 17:55	11.36	82%	124.7°
2034-01-09 Mon	100	—	unknown	18:50–23:50 (good, 5.0 h)	89.6° 17:50	11.34	74%	133.0°
2034-01-10 Tue	100	—	unknown	18:50–23:50 (good, 5.0 h)	89.8° 17:45	11.32	65%	139.6°
2034-01-11 Wed	100	—	unknown	18:50–23:50 (good, 5.0 h)	89.7° 17:40	11.3	56%	143.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-12-13&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.