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.

2034-07-12astronomy score per night — click a bar for that night2034-08-10

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-07-12 Wed	—	unknown	—	42.9° 11:35	4.88	11%	25.8°
2034-07-13 Thu	—	unknown	—	42.9° 11:30	4.92	5%	23.9°
2034-07-14 Fri	—	unknown	—	42.9° 11:25	4.96	1%	29.6°
2034-07-15 Sat	—	unknown	—	42.9° 11:20	5.0	0%	39.5°
2034-07-16 Sun	—	unknown	—	42.9° 11:15	5.04	2%	51.0°
2034-07-17 Mon	—	unknown	—	42.9° 11:15	5.09	6%	63.0°
2034-07-18 Tue	—	unknown	—	42.9° 11:10	5.13	12%	74.9°
2034-07-19 Wed	—	unknown	—	42.9° 11:05	5.18	19%	86.7°
2034-07-20 Thu	—	unknown	—	42.9° 11:00	5.23	28%	98.2°
2034-07-21 Fri	—	unknown	—	42.9° 10:55	5.28	37%	109.4°
2034-07-22 Sat	—	unknown	—	42.9° 10:55	5.33	47%	120.2°
2034-07-23 Sun	—	unknown	—	42.9° 10:50	5.38	56%	130.5°
2034-07-24 Mon	—	unknown	—	42.9° 10:45	5.43	65%	140.2°
2034-07-25 Tue	—	unknown	—	42.9° 10:40	5.48	74%	148.8°
2034-07-26 Wed	—	unknown	—	42.9° 10:40	5.53	82%	154.8°
2034-07-27 Thu	—	unknown	—	42.9° 10:35	5.58	89%	156.3°
2034-07-28 Fri	—	unknown	—	42.9° 10:30	5.63	94%	152.1°
2034-07-29 Sat	—	unknown	—	42.9° 10:25	5.69	98%	144.0°
2034-07-30 Sun	—	unknown	—	42.9° 10:20	5.74	100%	133.9°
2034-07-31 Mon	—	unknown	—	42.9° 10:20	5.8	99%	122.6°
2034-08-01 Tue	—	unknown	—	42.9° 10:15	5.85	97%	110.6°
2034-08-02 Wed	—	unknown	—	42.9° 10:10	5.91	92%	98.2°
2034-08-03 Thu	—	unknown	—	42.9° 10:05	5.96	85%	85.6°
2034-08-04 Fri	—	unknown	—	42.9° 10:00	6.02	76%	72.8°
2034-08-05 Sat	—	unknown	—	42.9° 10:00	6.07	65%	60.2°
2034-08-06 Sun	—	unknown	—	42.9° 09:55	6.13	54%	47.9°
2034-08-07 Mon	—	unknown	—	42.9° 09:50	6.19	42%	36.6°
2034-08-08 Tue	—	unknown	—	42.9° 09:45	6.24	31%	27.5°
2034-08-09 Wed	—	unknown	—	42.9° 09:45	6.3	21%	23.5°
2034-08-10 Thu	—	unknown	—	42.9° 09:40	6.36	13%	27.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-07-12&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.