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: 01-05 (100), 01-06 (100), 01-07 (100), 01-08 (100), 01-09 (100) — by astronomy; check the weather when the night is within four days.

2045-01-01astronomy score per night — click a bar for that night2045-01-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-01-01 Sun	34	—	unknown	18:45–00:15 (marginal, 5.5 h)	89.8° 18:20	11.45	96%	56.6°
2045-01-02 Mon	49	—	unknown	18:45–19:10 (good, 0.42 h)	89.8° 18:15	11.43	100%	69.3°
2045-01-03 Tue	69	—	unknown	18:45–21:40 (good, 2.92 h)	89.7° 18:10	11.42	100%	82.5°
2045-01-04 Wed	83	—	unknown	18:45–23:15 (good, 4.5 h)	89.5° 18:10	11.41	96%	95.8°
2045-01-05 Thu	100	—	unknown	18:45–23:50 (good, 5.08 h)	89.7° 18:05	11.4	91%	108.9°
2045-01-06 Fri	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.8° 18:00	11.38	83%	121.3°
2045-01-07 Sat	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.8° 17:55	11.37	73%	132.6°
2045-01-08 Sun	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.6° 17:50	11.35	63%	142.2°
2045-01-09 Mon	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.6° 17:50	11.33	52%	148.8°
2045-01-10 Tue	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.7° 17:45	11.32	42%	150.9°
2045-01-11 Wed	100	—	unknown	18:55–23:50 (good, 4.92 h)	89.8° 17:40	11.3	32%	148.1°
2045-01-12 Thu	100	—	unknown	18:55–23:45 (good, 4.83 h)	89.7° 17:35	11.28	23%	141.7°
2045-01-13 Fri	100	—	unknown	18:55–23:40 (good, 4.75 h)	89.6° 17:30	11.26	16%	133.4°
2045-01-14 Sat	100	—	unknown	18:55–23:35 (good, 4.67 h)	89.6° 17:30	11.24	9%	124.0°
2045-01-15 Sun	100	—	unknown	18:55–23:35 (good, 4.67 h)	89.8° 17:25	11.22	5%	114.1°
2045-01-16 Mon	100	—	unknown	19:00–23:30 (good, 4.5 h)	89.8° 17:20	11.19	2%	103.9°
2045-01-17 Tue	100	—	unknown	19:00–23:25 (good, 4.42 h)	89.7° 17:15	11.17	0%	93.6°
2045-01-18 Wed	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.5° 17:15	11.15	0%	83.3°
2045-01-19 Thu	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.7° 17:10	11.12	3%	73.0°
2045-01-20 Fri	100	—	unknown	19:00–23:15 (good, 4.25 h)	89.8° 17:05	11.1	7%	62.8°
2045-01-21 Sat	96	—	unknown	19:05–23:10 (good, 4.08 h)	89.8° 17:00	11.07	12%	53.0°
2045-01-22 Sun	90	—	unknown	19:05–23:05 (good, 4.0 h)	89.6° 16:55	11.05	19%	43.7°
2045-01-23 Mon	76	—	unknown	19:05–23:00 (good, 3.92 h)	89.6° 16:55	11.02	27%	35.8°
2045-01-24 Tue	59	—	unknown	19:05–22:35 (good, 3.5 h)	89.7° 16:50	10.99	37%	30.3°
2045-01-25 Wed	45	—	unknown	19:05–21:30 (good, 2.42 h)	89.8° 16:45	10.96	47%	29.2°
2045-01-26 Thu	33	—	unknown	19:10–23:15 (marginal, 4.08 h)	89.7° 16:40	10.93	58%	33.1°
2045-01-27 Fri	26	—	unknown	19:10–23:00 (marginal, 3.83 h)	89.6° 16:35	10.9	68%	41.1°
2045-01-28 Sat	24	—	unknown	19:10–22:45 (marginal, 3.58 h)	89.6° 16:35	10.87	78%	51.5°
2045-01-29 Sun	26	—	unknown	19:10–22:45 (marginal, 3.58 h)	89.8° 16:30	10.84	87%	63.5°
2045-01-30 Mon	32	—	unknown	19:10–19:25 (good, 0.25 h)	89.8° 16:25	10.81	94%	76.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-01-01&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.