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: 02-15 (50), 02-16 (50), 02-17 (48), 02-14 (45), 02-18 (45) — by astronomy; check the weather when the night is within four days.

2044-02-14astronomy score per night — click a bar for that night2044-03-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-02-14 Sun	45	—	unknown	19:30–21:25 (good, 1.92 h)	89.8° 15:30	10.3	96%	129.2°
2044-02-15 Mon	50	—	unknown	19:30–21:25 (good, 1.92 h)	89.8° 15:25	10.26	92%	138.8°
2044-02-16 Tue	50	—	unknown	19:30–21:30 (good, 2.0 h)	89.7° 15:20	10.22	85%	146.1°
2044-02-17 Wed	48	—	unknown	19:30–21:25 (good, 1.92 h)	89.5° 15:15	10.18	77%	149.7°
2044-02-18 Thu	45	—	unknown	19:35–21:25 (good, 1.83 h)	89.7° 15:15	10.14	68%	148.8°
2044-02-19 Fri	43	—	unknown	19:35–21:20 (good, 1.75 h)	89.8° 15:10	10.1	59%	144.0°
2044-02-20 Sat	42	—	unknown	19:35–21:15 (good, 1.67 h)	89.8° 15:05	10.06	49%	136.8°
2044-02-21 Sun	40	—	unknown	19:35–21:10 (good, 1.58 h)	89.6° 15:00	10.01	40%	128.1°
2044-02-22 Mon	37	—	unknown	19:40–21:05 (good, 1.42 h)	89.6° 15:00	9.97	31%	118.7°
2044-02-23 Tue	36	—	unknown	19:40–21:05 (good, 1.42 h)	89.7° 14:55	9.93	22%	108.8°
2044-02-24 Wed	34	—	unknown	19:40–21:00 (good, 1.33 h)	89.8° 14:50	9.89	15%	98.4°
2044-02-25 Thu	33	—	unknown	19:40–20:55 (good, 1.25 h)	89.7° 14:45	9.84	9%	87.9°
2044-02-26 Fri	31	—	unknown	19:40–20:50 (good, 1.17 h)	89.6° 14:40	9.8	4%	77.1°
2044-02-27 Sat	29	—	unknown	19:45–20:45 (good, 1.0 h)	89.6° 14:40	9.75	1%	66.3°
2044-02-28 Sun	27	—	unknown	19:45–20:45 (good, 1.0 h)	89.8° 14:35	9.71	0%	55.6°
2044-02-29 Mon	25	—	unknown	19:45–20:40 (good, 0.92 h)	89.8° 14:30	9.66	1%	45.5°
2044-03-01 Tue	24	—	unknown	19:45–20:35 (good, 0.83 h)	89.7° 14:25	9.62	5%	36.8°
2044-03-02 Wed	20	—	unknown	19:50–20:25 (good, 0.58 h)	89.5° 14:20	9.57	11%	31.2°
2044-03-03 Thu	16	—	unknown	19:50–20:15 (good, 0.42 h)	89.7° 14:20	9.53	19%	30.4°
2044-03-04 Fri	13	—	unknown	19:50–20:05 (good, 0.25 h)	89.8° 14:15	9.48	28%	35.1°
2044-03-05 Sat	10	—	unknown	19:20–20:55 (marginal, 1.58 h)	89.8° 14:10	9.43	39%	43.6°
2044-03-06 Sun	7	—	unknown	19:55–20:45 (marginal, 0.83 h)	89.6° 14:05	9.38	51%	54.0°
2044-03-07 Mon	6	—	unknown	19:55–20:35 (marginal, 0.67 h)	89.5° 14:05	9.34	62%	65.6°
2044-03-08 Tue	5	—	unknown	19:55–20:35 (marginal, 0.67 h)	89.7° 14:00	9.29	73%	77.6°
2044-03-09 Wed	5	—	unknown	19:55–20:30 (marginal, 0.58 h)	89.8° 13:55	9.24	82%	89.8°
2044-03-10 Thu	5	—	unknown	19:55–20:35 (marginal, 0.67 h)	89.7° 13:50	9.19	90%	102.0°
2044-03-11 Fri	5	—	unknown	20:00–20:30 (marginal, 0.5 h)	89.6° 13:45	9.14	96%	113.8°
2044-03-12 Sat	5	—	unknown	20:00–20:25 (marginal, 0.42 h)	89.6° 13:45	9.09	99%	125.0°
2044-03-13 Sun	4	—	unknown	20:00–20:20 (marginal, 0.33 h)	89.8° 13:40	9.04	100%	135.2°
2044-03-14 Mon	3	—	unknown	20:00–20:15 (marginal, 0.25 h)	89.8° 13:35	8.99	99%	143.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-02-14&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.