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 Seven Sisters: 07-11 (2), 07-07 (1), 07-08 (1), 07-09 (1), 07-10 (1) — by astronomy; check the weather when the night is within four days.

2029-06-12astronomy score per night — click a bar for that night2029-07-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-06-12 Tue	0	—	unknown	—	72.5° 11:40	4.49	1%	31.7°
2029-06-13 Wed	0	—	unknown	—	72.5° 11:35	4.48	3%	44.5°
2029-06-14 Thu	0	—	unknown	—	72.5° 11:35	4.46	8%	57.6°
2029-06-15 Fri	0	—	unknown	—	72.5° 11:30	4.45	15%	71.0°
2029-06-16 Sat	0	—	unknown	—	72.5° 11:25	4.44	24%	84.5°
2029-06-17 Sun	0	—	unknown	—	72.5° 11:20	4.43	34%	98.2°
2029-06-18 Mon	0	—	unknown	—	72.5° 11:20	4.43	44%	112.1°
2029-06-19 Tue	0	—	unknown	—	72.5° 11:15	4.42	56%	126.2°
2029-06-20 Wed	0	—	unknown	—	72.5° 11:10	4.42	67%	140.5°
2029-06-21 Thu	0	—	unknown	—	72.5° 11:05	4.42	78%	154.9°
2029-06-22 Fri	0	—	unknown	—	72.5° 11:00	4.43	87%	169.3°
2029-06-23 Sat	0	—	unknown	—	72.5° 11:00	4.43	94%	176.0°
2029-06-24 Sun	0	—	unknown	—	72.5° 10:55	4.44	98%	161.8°
2029-06-25 Mon	0	—	unknown	—	72.5° 10:50	4.45	100%	147.6°
2029-06-26 Tue	0	—	unknown	—	72.5° 10:45	4.46	99%	133.7°
2029-06-27 Wed	0	—	unknown	—	72.5° 10:40	4.47	96%	120.1°
2029-06-28 Thu	0	—	unknown	—	72.5° 10:40	4.49	91%	106.9°
2029-06-29 Fri	0	—	unknown	—	72.5° 10:35	4.5	84%	94.0°
2029-06-30 Sat	0	—	unknown	—	72.5° 10:30	4.52	76%	81.5°
2029-07-01 Sun	0	—	unknown	—	72.5° 10:25	4.54	67%	69.3°
2029-07-02 Mon	0	—	unknown	—	72.5° 10:25	4.57	58%	57.2°
2029-07-03 Tue	0	—	unknown	—	72.5° 10:20	4.59	48%	45.3°
2029-07-04 Wed	0	—	unknown	—	72.5° 10:15	4.62	39%	33.5°
2029-07-05 Thu	0	—	unknown	—	72.5° 10:10	4.65	30%	21.6°
2029-07-06 Fri	0	—	unknown	—	72.5° 10:05	4.68	21%	9.7°
2029-07-07 Sat	1	—	unknown	—	72.5° 10:05	4.71	14%	2.8°
2029-07-08 Sun	1	—	unknown	—	72.5° 10:00	4.74	8%	15.0°
2029-07-09 Mon	1	—	unknown	—	72.5° 09:55	4.77	3%	27.6°
2029-07-10 Tue	1	—	unknown	—	72.5° 09:50	4.81	1%	40.6°
2029-07-11 Wed	2	—	unknown	04:40–04:45 (marginal, 0.08 h)	72.5° 09:45	4.85	0%	53.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-06-12&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.