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: 12-14 (100), 12-15 (100), 12-16 (100), 12-17 (100), 12-18 (100) — by astronomy; check the weather when the night is within four days.

2036-12-14astronomy score per night — click a bar for that night2037-01-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-12-14 Sun	100	—	unknown	18:35–01:40 (good, 7.08 h)	89.8° 19:30	11.49	8%	135.8°
2036-12-15 Mon	100	—	unknown	18:35–01:35 (good, 7.0 h)	89.7° 19:25	11.49	3%	128.8°
2036-12-16 Tue	100	—	unknown	18:35–01:30 (good, 6.92 h)	89.6° 19:20	11.5	1%	120.3°
2036-12-17 Wed	100	—	unknown	18:35–01:25 (good, 6.83 h)	89.6° 19:20	11.5	0%	111.2°
2036-12-18 Thu	100	—	unknown	18:35–01:25 (good, 6.83 h)	89.7° 19:15	11.5	2%	101.7°
2036-12-19 Fri	100	—	unknown	18:35–01:20 (good, 6.75 h)	89.8° 19:10	11.51	5%	92.1°
2036-12-20 Sat	100	—	unknown	18:35–01:15 (good, 6.67 h)	89.7° 19:05	11.51	10%	82.6°
2036-12-21 Sun	100	—	unknown	18:35–01:10 (good, 6.58 h)	89.5° 19:00	11.51	16%	73.4°
2036-12-22 Mon	100	—	unknown	18:35–01:05 (good, 6.5 h)	89.6° 19:00	11.51	24%	64.6°
2036-12-23 Tue	94	—	unknown	18:40–01:05 (good, 6.42 h)	89.8° 18:55	11.5	32%	56.4°
2036-12-24 Wed	87	—	unknown	18:40–01:00 (good, 6.33 h)	89.7° 18:50	11.5	42%	49.0°
2036-12-25 Thu	80	—	unknown	18:40–00:55 (good, 6.25 h)	89.6° 18:45	11.5	51%	43.1°
2036-12-26 Fri	64	—	unknown	18:40–23:35 (good, 4.92 h)	89.5° 18:45	11.49	61%	39.3°
2036-12-27 Sat	49	—	unknown	18:40–01:15 (marginal, 6.58 h)	89.7° 18:40	11.49	70%	38.6°
2036-12-28 Sun	39	—	unknown	18:40–01:00 (marginal, 6.33 h)	89.8° 18:35	11.48	79%	41.3°
2036-12-29 Mon	36	—	unknown	18:40–00:40 (marginal, 6.0 h)	89.7° 18:30	11.47	87%	47.2°
2036-12-30 Tue	38	—	unknown	18:40–00:30 (marginal, 5.83 h)	89.6° 18:25	11.47	94%	55.4°
2036-12-31 Wed	46	—	unknown	18:45–00:30 (marginal, 5.75 h)	89.6° 18:25	11.46	98%	65.3°
2037-01-01 Thu	60	—	unknown	18:45–21:00 (good, 2.25 h)	89.7° 18:20	11.45	100%	76.2°
2037-01-02 Fri	77	—	unknown	18:45–22:20 (good, 3.58 h)	89.8° 18:15	11.44	99%	87.7°
2037-01-03 Sat	100	—	unknown	18:45–23:40 (good, 4.92 h)	89.7° 18:10	11.42	95%	99.3°
2037-01-04 Sun	100	—	unknown	18:45–23:55 (good, 5.17 h)	89.5° 18:05	11.41	89%	110.7°
2037-01-05 Mon	100	—	unknown	18:45–00:00 (good, 5.25 h)	89.6° 18:05	11.4	80%	121.2°
2037-01-06 Tue	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.8° 18:00	11.38	70%	130.4°
2037-01-07 Wed	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.8° 17:55	11.37	59%	137.4°
2037-01-08 Thu	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.6° 17:50	11.35	48%	141.1°
2037-01-09 Fri	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.5° 17:50	11.34	37%	140.9°
2037-01-10 Sat	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.7° 17:45	11.32	27%	137.0°
2037-01-11 Sun	100	—	unknown	18:55–23:50 (good, 4.92 h)	89.8° 17:40	11.3	19%	130.5°
2037-01-12 Mon	100	—	unknown	18:55–23:45 (good, 4.83 h)	89.7° 17:35	11.28	11%	122.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-12-14&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.