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: 04-26 (1), 04-27 (1), 04-28 (1), 04-29 (1), 04-30 (1) — by astronomy; check the weather when the night is within four days.

2036-04-05astronomy score per night — click a bar for that night2036-05-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-04-05 Sat	0	—	unknown	—	89.7° 13:10	7.83	72%	102.6°
2036-04-06 Sun	0	—	unknown	—	89.8° 13:05	7.77	81%	113.4°
2036-04-07 Mon	0	—	unknown	—	89.7° 13:00	7.72	89%	123.6°
2036-04-08 Tue	0	—	unknown	—	89.6° 12:55	7.66	95%	132.4°
2036-04-09 Wed	0	—	unknown	—	89.5° 12:55	7.6	99%	138.9°
2036-04-10 Thu	0	—	unknown	—	89.7° 12:50	7.55	100%	142.0°
2036-04-11 Fri	0	—	unknown	—	89.8° 12:45	7.49	98%	141.0°
2036-04-12 Sat	0	—	unknown	—	89.7° 12:40	7.43	95%	136.4°
2036-04-13 Sun	0	—	unknown	—	89.5° 12:35	7.38	89%	129.5°
2036-04-14 Mon	0	—	unknown	—	89.6° 12:35	7.32	82%	121.3°
2036-04-15 Tue	0	—	unknown	—	89.7° 12:30	7.26	74%	112.4°
2036-04-16 Wed	0	—	unknown	—	89.8° 12:25	7.2	66%	103.2°
2036-04-17 Thu	0	—	unknown	—	89.7° 12:20	7.14	56%	93.9°
2036-04-18 Fri	0	—	unknown	—	89.5° 12:15	7.09	47%	84.6°
2036-04-19 Sat	0	—	unknown	—	89.6° 12:15	7.03	37%	75.3°
2036-04-20 Sun	0	—	unknown	—	89.8° 12:10	6.97	28%	66.2°
2036-04-21 Mon	0	—	unknown	—	89.7° 12:05	6.91	20%	57.5°
2036-04-22 Tue	0	—	unknown	—	89.6° 12:00	6.85	13%	49.6°
2036-04-23 Wed	0	—	unknown	—	89.7° 11:55	6.8	7%	43.0°
2036-04-24 Thu	0	—	unknown	—	89.8° 11:50	6.74	3%	38.8°
2036-04-25 Fri	0	—	unknown	—	89.7° 11:45	6.68	0%	38.1°
2036-04-26 Sat	1	—	unknown	—	89.5° 11:40	6.62	0%	41.3°
2036-04-27 Sun	1	—	unknown	—	89.6° 11:40	6.56	3%	47.8°
2036-04-28 Mon	1	—	unknown	—	89.7° 11:35	6.5	8%	56.5°
2036-04-29 Tue	1	—	unknown	—	89.8° 11:30	6.45	15%	66.7°
2036-04-30 Wed	1	—	unknown	—	89.7° 11:25	6.39	25%	77.5°
2036-05-01 Thu	1	—	unknown	—	89.5° 11:20	6.33	35%	88.7°
2036-05-02 Fri	1	—	unknown	—	89.6° 11:20	6.27	46%	99.9°
2036-05-03 Sat	1	—	unknown	—	89.8° 11:15	6.21	58%	110.8°
2036-05-04 Sun	1	—	unknown	—	89.7° 11:10	6.16	69%	121.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-04-05&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.