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: 05-06 (2), 05-07 (2), 04-29 (1), 04-30 (1), 05-01 (1) — by astronomy; check the weather when the night is within four days.

2035-04-08astronomy score per night — click a bar for that night2035-05-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-04-08 Sun	0	—	unknown	—	89.8° 13:00	7.7	0%	36.9°
2035-04-09 Mon	0	—	unknown	—	89.7° 12:55	7.65	3%	39.3°
2035-04-10 Tue	0	—	unknown	—	89.6° 12:50	7.59	8%	45.8°
2035-04-11 Wed	0	—	unknown	—	89.5° 12:50	7.53	16%	54.9°
2035-04-12 Thu	0	—	unknown	—	89.7° 12:45	7.48	26%	65.3°
2035-04-13 Fri	0	—	unknown	—	89.8° 12:40	7.42	37%	76.4°
2035-04-14 Sat	0	—	unknown	—	89.7° 12:35	7.36	48%	87.6°
2035-04-15 Sun	0	—	unknown	—	89.5° 12:30	7.3	59%	98.7°
2035-04-16 Mon	0	—	unknown	—	89.6° 12:30	7.25	70%	109.4°
2035-04-17 Tue	0	—	unknown	—	89.7° 12:25	7.19	79%	119.5°
2035-04-18 Wed	0	—	unknown	—	89.8° 12:20	7.13	87%	128.5°
2035-04-19 Thu	0	—	unknown	—	89.6° 12:15	7.07	93%	136.0°
2035-04-20 Fri	0	—	unknown	—	89.5° 12:15	7.01	97%	141.2°
2035-04-21 Sat	0	—	unknown	—	89.7° 12:10	6.96	100%	143.2°
2035-04-22 Sun	0	—	unknown	—	89.8° 12:05	6.9	100%	141.6°
2035-04-23 Mon	0	—	unknown	—	89.7° 12:00	6.84	98%	137.0°
2035-04-24 Tue	0	—	unknown	—	89.5° 11:55	6.78	94%	130.3°
2035-04-25 Wed	0	—	unknown	—	89.7° 11:50	6.72	90%	122.4°
2035-04-26 Thu	0	—	unknown	—	89.8° 11:45	6.67	83%	113.8°
2035-04-27 Fri	0	—	unknown	—	89.7° 11:40	6.61	75%	104.6°
2035-04-28 Sat	0	—	unknown	—	89.5° 11:35	6.55	67%	95.2°
2035-04-29 Sun	1	—	unknown	—	89.6° 11:35	6.49	57%	85.7°
2035-04-30 Mon	1	—	unknown	—	89.7° 11:30	6.43	48%	76.0°
2035-05-01 Tue	1	—	unknown	—	89.8° 11:25	6.37	38%	66.4°
2035-05-02 Wed	1	—	unknown	—	89.6° 11:20	6.32	28%	57.0°
2035-05-03 Thu	1	—	unknown	—	89.5° 11:15	6.26	19%	48.4°
2035-05-04 Fri	1	—	unknown	—	89.6° 11:15	6.2	11%	41.4°
2035-05-05 Sat	1	—	unknown	—	89.8° 11:10	6.14	5%	37.3°
2035-05-06 Sun	2	—	unknown	05:00–05:05 (marginal, 0.08 h)	89.7° 11:05	6.09	1%	37.7°
2035-05-07 Mon	2	—	unknown	05:00–05:05 (marginal, 0.08 h)	89.6° 11:00	6.03	0%	42.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-04-08&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.