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: 02-09 (64), 02-10 (62), 02-11 (58), 02-12 (53), 02-13 (44) — by astronomy; check the weather when the night is within four days.

2043-02-09astronomy score per night — click a bar for that night2043-03-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-02-09 Mon	64	—	unknown	19:25–21:55 (good, 2.5 h)	89.6° 15:50	10.48	0%	72.4°
2043-02-10 Tue	62	—	unknown	19:25–21:55 (good, 2.5 h)	89.7° 15:45	10.44	2%	60.9°
2043-02-11 Wed	58	—	unknown	19:25–21:50 (good, 2.42 h)	89.8° 15:40	10.41	5%	50.0°
2043-02-12 Thu	53	—	unknown	19:25–21:45 (good, 2.33 h)	89.7° 15:35	10.37	12%	40.4°
2043-02-13 Fri	44	—	unknown	19:30–21:30 (good, 2.0 h)	89.5° 15:30	10.33	20%	33.7°
2043-02-14 Sat	35	—	unknown	19:30–21:20 (good, 1.83 h)	89.6° 15:30	10.29	30%	31.6°
2043-02-15 Sun	26	—	unknown	19:30–20:50 (good, 1.33 h)	89.8° 15:25	10.25	41%	35.1°
2043-02-16 Mon	21	—	unknown	19:30–21:55 (marginal, 2.42 h)	89.8° 15:20	10.21	53%	42.7°
2043-02-17 Tue	17	—	unknown	19:30–21:45 (marginal, 2.25 h)	89.7° 15:15	10.17	64%	52.4°
2043-02-18 Wed	16	—	unknown	19:35–21:35 (marginal, 2.0 h)	89.5° 15:15	10.13	74%	63.2°
2043-02-19 Thu	16	—	unknown	19:35–21:35 (marginal, 2.0 h)	89.7° 15:10	10.09	83%	74.5°
2043-02-20 Fri	18	—	unknown	19:35–21:35 (marginal, 2.0 h)	89.8° 15:05	10.05	90%	85.9°
2043-02-21 Sat	21	—	unknown	19:35–20:15 (good, 0.67 h)	89.8° 15:00	10.0	96%	97.2°
2043-02-22 Sun	24	—	unknown	19:40–20:40 (good, 1.0 h)	89.6° 14:55	9.96	99%	108.3°
2043-02-23 Mon	28	—	unknown	19:40–20:50 (good, 1.17 h)	89.6° 14:55	9.92	100%	118.8°
2043-02-24 Tue	27	—	unknown	19:40–20:45 (good, 1.08 h)	89.7° 14:50	9.88	99%	128.6°
2043-02-25 Wed	30	—	unknown	19:40–20:45 (good, 1.08 h)	89.8° 14:45	9.83	96%	137.2°
2043-02-26 Thu	30	—	unknown	19:40–20:50 (good, 1.17 h)	89.7° 14:40	9.79	91%	144.0°
2043-02-27 Fri	28	—	unknown	19:45–20:45 (good, 1.0 h)	89.6° 14:35	9.74	85%	147.9°
2043-02-28 Sat	26	—	unknown	19:45–20:40 (good, 0.92 h)	89.6° 14:35	9.7	78%	148.0°
2043-03-01 Sun	25	—	unknown	19:45–20:40 (good, 0.92 h)	89.8° 14:30	9.65	70%	144.4°
2043-03-02 Mon	23	—	unknown	19:45–20:35 (good, 0.83 h)	89.8° 14:25	9.61	60%	138.0°
2043-03-03 Tue	22	—	unknown	19:50–20:30 (good, 0.67 h)	89.7° 14:20	9.56	51%	129.9°
2043-03-04 Wed	20	—	unknown	19:50–20:25 (good, 0.58 h)	89.5° 14:20	9.51	41%	120.6°
2043-03-05 Thu	18	—	unknown	19:50–20:25 (good, 0.58 h)	89.7° 14:15	9.47	32%	110.6°
2043-03-06 Fri	17	—	unknown	19:50–20:20 (good, 0.5 h)	89.8° 14:10	9.42	23%	99.9°
2043-03-07 Sat	14	—	unknown	19:55–20:15 (good, 0.33 h)	89.8° 14:05	9.37	15%	88.8°
2043-03-08 Sun	13	—	unknown	19:55–20:10 (good, 0.25 h)	89.6° 14:00	9.33	8%	77.3°
2043-03-09 Mon	11	—	unknown	19:55–20:05 (good, 0.17 h)	89.6° 14:00	9.28	3%	65.7°
2043-03-10 Tue	10	—	unknown	19:55–20:05 (good, 0.17 h)	89.7° 13:55	9.23	0%	54.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-02-09&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.