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: 04-12 (1), 04-13 (1), 04-14 (1) — by astronomy; check the weather when the night is within four days.

2034-04-12astronomy score per night — click a bar for that night2034-05-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-04-12 Wed	1	—	unknown	—	72.5° 15:45	7.46	40%	114.5°
2034-04-13 Thu	1	—	unknown	—	72.5° 15:40	7.4	30%	101.4°
2034-04-14 Fri	1	—	unknown	—	72.5° 15:40	7.35	20%	87.8°
2034-04-15 Sat	0	—	unknown	—	72.5° 15:35	7.29	12%	73.7°
2034-04-16 Sun	0	—	unknown	—	72.5° 15:30	7.23	5%	59.2°
2034-04-17 Mon	0	—	unknown	—	72.5° 15:25	7.17	1%	44.5°
2034-04-18 Tue	0	—	unknown	—	72.5° 15:25	7.12	0%	29.8°
2034-04-19 Wed	0	—	unknown	—	72.5° 15:20	7.06	2%	15.8°
2034-04-20 Thu	0	—	unknown	—	72.5° 15:15	7.0	7%	8.7°
2034-04-21 Fri	0	—	unknown	—	72.5° 15:10	6.94	14%	18.5°
2034-04-22 Sat	0	—	unknown	—	72.5° 15:05	6.88	23%	32.0°
2034-04-23 Sun	0	—	unknown	—	72.5° 15:05	6.83	33%	45.6°
2034-04-24 Mon	0	—	unknown	—	72.5° 15:00	6.77	44%	58.9°
2034-04-25 Tue	0	—	unknown	—	72.5° 14:55	6.71	55%	71.8°
2034-04-26 Wed	0	—	unknown	—	72.5° 14:50	6.65	65%	84.5°
2034-04-27 Thu	0	—	unknown	—	72.5° 14:45	6.59	74%	96.8°
2034-04-28 Fri	0	—	unknown	—	72.5° 14:45	6.53	82%	108.9°
2034-04-29 Sat	0	—	unknown	—	72.5° 14:40	6.48	89%	120.9°
2034-04-30 Sun	0	—	unknown	—	72.5° 14:35	6.42	94%	132.6°
2034-05-01 Mon	0	—	unknown	—	72.5° 14:30	6.36	98%	144.2°
2034-05-02 Tue	0	—	unknown	—	72.5° 14:30	6.3	100%	155.5°
2034-05-03 Wed	0	—	unknown	—	72.5° 14:25	6.24	100%	166.0°
2034-05-04 Thu	0	—	unknown	—	72.5° 14:20	6.19	98%	171.5°
2034-05-05 Fri	0	—	unknown	—	72.5° 14:15	6.13	95%	164.9°
2034-05-06 Sat	0	—	unknown	—	72.5° 14:10	6.07	90%	154.1°
2034-05-07 Sun	0	—	unknown	—	72.5° 14:10	6.02	83%	142.5°
2034-05-08 Mon	0	—	unknown	—	72.5° 14:05	5.96	75%	130.5°
2034-05-09 Tue	0	—	unknown	—	72.5° 14:00	5.9	66%	118.1°
2034-05-10 Wed	0	—	unknown	—	72.5° 13:55	5.85	56%	105.5°
2034-05-11 Thu	0	—	unknown	—	72.5° 13:50	5.79	45%	92.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-04-12&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.