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.

2029-07-05astronomy score per night — click a bar for that night2029-08-03

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-07-05 Thu	—	unknown	—	42.9° 12:00	4.65	30%	54.4°
2029-07-06 Fri	—	unknown	—	42.9° 11:55	4.68	21%	45.3°
2029-07-07 Sat	—	unknown	—	42.9° 11:50	4.71	14%	37.3°
2029-07-08 Sun	—	unknown	—	42.9° 11:45	4.74	8%	31.5°
2029-07-09 Mon	—	unknown	—	42.9° 11:45	4.77	3%	29.6°
2029-07-10 Tue	—	unknown	—	42.9° 11:40	4.81	1%	32.6°
2029-07-11 Wed	—	unknown	—	42.9° 11:35	4.85	0%	39.5°
2029-07-12 Thu	—	unknown	—	42.9° 11:30	4.89	2%	49.0°
2029-07-13 Fri	—	unknown	—	42.9° 11:30	4.93	6%	59.8°
2029-07-14 Sat	—	unknown	—	42.9° 11:25	4.97	13%	71.5°
2029-07-15 Sun	—	unknown	—	42.9° 11:20	5.01	21%	83.6°
2029-07-16 Mon	—	unknown	—	42.9° 11:15	5.05	31%	95.9°
2029-07-17 Tue	—	unknown	—	42.9° 11:10	5.1	42%	108.1°
2029-07-18 Wed	—	unknown	—	42.9° 11:10	5.14	54%	120.0°
2029-07-19 Thu	—	unknown	—	42.9° 11:05	5.19	65%	131.3°
2029-07-20 Fri	—	unknown	—	42.9° 11:00	5.24	76%	141.1°
2029-07-21 Sat	—	unknown	—	42.9° 10:55	5.29	85%	148.1°
2029-07-22 Sun	—	unknown	—	42.9° 10:50	5.34	92%	150.4°
2029-07-23 Mon	—	unknown	—	42.9° 10:50	5.39	97%	147.0°
2029-07-24 Tue	—	unknown	—	42.9° 10:45	5.44	100%	139.7°
2029-07-25 Wed	—	unknown	—	42.9° 10:40	5.49	100%	130.2°
2029-07-26 Thu	—	unknown	—	42.9° 10:35	5.54	98%	119.9°
2029-07-27 Fri	—	unknown	—	42.9° 10:35	5.59	94%	109.2°
2029-07-28 Sat	—	unknown	—	42.9° 10:30	5.65	88%	98.5°
2029-07-29 Sun	—	unknown	—	42.9° 10:25	5.7	81%	87.9°
2029-07-30 Mon	—	unknown	—	42.9° 10:20	5.75	73%	77.5°
2029-07-31 Tue	—	unknown	—	42.9° 10:15	5.81	64%	67.3°
2029-08-01 Wed	—	unknown	—	42.9° 10:15	5.86	55%	57.5°
2029-08-02 Thu	—	unknown	—	42.9° 10:10	5.92	46%	48.2°
2029-08-03 Fri	—	unknown	—	42.9° 10:05	5.97	36%	39.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-07-05&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.