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.

2036-07-01astronomy score per night — click a bar for that night2036-07-30

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-07-01 Tue	—	unknown	—	42.9° 12:20	4.55	63%	120.5°
2036-07-02 Wed	—	unknown	—	42.9° 12:15	4.57	72%	131.7°
2036-07-03 Thu	—	unknown	—	42.9° 12:10	4.6	81%	141.8°
2036-07-04 Fri	—	unknown	—	42.9° 12:05	4.63	88%	150.1°
2036-07-05 Sat	—	unknown	—	42.9° 12:00	4.65	94%	155.0°
2036-07-06 Sun	—	unknown	—	42.9° 11:55	4.69	98%	154.7°
2036-07-07 Mon	—	unknown	—	42.9° 11:50	4.72	100%	149.5°
2036-07-08 Tue	—	unknown	—	42.9° 11:45	4.75	100%	141.5°
2036-07-09 Wed	—	unknown	—	42.9° 11:45	4.79	98%	132.0°
2036-07-10 Thu	—	unknown	—	42.9° 11:40	4.82	95%	121.9°
2036-07-11 Fri	—	unknown	—	42.9° 11:35	4.86	90%	111.4°
2036-07-12 Sat	—	unknown	—	42.9° 11:30	4.9	83%	100.7°
2036-07-13 Sun	—	unknown	—	42.9° 11:25	4.94	75%	89.8°
2036-07-14 Mon	—	unknown	—	42.9° 11:25	4.98	66%	78.7°
2036-07-15 Tue	—	unknown	—	42.9° 11:20	5.02	57%	67.6°
2036-07-16 Wed	—	unknown	—	42.9° 11:15	5.07	47%	56.4°
2036-07-17 Thu	—	unknown	—	42.9° 11:10	5.11	36%	45.4°
2036-07-18 Fri	—	unknown	—	42.9° 11:05	5.16	26%	35.1°
2036-07-19 Sat	—	unknown	—	42.9° 11:05	5.2	17%	27.0°
2036-07-20 Sun	—	unknown	—	42.9° 11:00	5.25	9%	24.4°
2036-07-21 Mon	—	unknown	—	42.9° 10:55	5.3	3%	29.4°
2036-07-22 Tue	—	unknown	—	42.9° 10:50	5.35	0%	39.5°
2036-07-23 Wed	—	unknown	—	42.9° 10:50	5.4	0%	51.9°
2036-07-24 Thu	—	unknown	—	42.9° 10:45	5.45	3%	65.1°
2036-07-25 Fri	—	unknown	—	42.9° 10:40	5.5	9%	78.7°
2036-07-26 Sat	—	unknown	—	42.9° 10:35	5.56	17%	92.0°
2036-07-27 Sun	—	unknown	—	42.9° 10:30	5.61	27%	105.0°
2036-07-28 Mon	—	unknown	—	42.9° 10:30	5.66	37%	117.4°
2036-07-29 Tue	—	unknown	—	42.9° 10:25	5.72	48%	129.0°
2036-07-30 Wed	—	unknown	—	42.9° 10:20	5.77	58%	139.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-07-01&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.