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 V1057 Cyg: 05-30 (100), 05-31 (100), 06-01 (100), 06-02 (100), 06-03 (100) — by astronomy; check the weather when the night is within four days.

2046-05-25astronomy score per night — click a bar for that night2046-06-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-05-25 Fri	78	—	unknown	23:50–03:55 (good, 4.08 h)	87.2° 06:05	5.07	67%	59.8°
2046-05-26 Sat	85	—	unknown	23:45–03:50 (good, 4.08 h)	87.2° 06:00	5.03	57%	56.4°
2046-05-27 Sun	92	—	unknown	23:45–03:50 (good, 4.08 h)	87.2° 06:00	4.99	48%	54.7°
2046-05-28 Mon	94	—	unknown	23:40–03:50 (good, 4.17 h)	87.3° 05:55	4.94	39%	54.6°
2046-05-29 Tue	97	—	unknown	23:35–03:50 (good, 4.25 h)	87.3° 05:50	4.9	30%	56.3°
2046-05-30 Wed	100	—	unknown	23:30–03:45 (good, 4.25 h)	87.2° 05:45	4.86	21%	59.5°
2046-05-31 Thu	100	—	unknown	23:30–03:45 (good, 4.25 h)	87.2° 05:45	4.83	14%	64.2°
2046-06-01 Fri	100	—	unknown	23:25–03:45 (good, 4.33 h)	87.2° 05:40	4.79	8%	69.9°
2046-06-02 Sat	100	—	unknown	23:20–03:45 (good, 4.42 h)	87.3° 05:35	4.75	3%	76.5°
2046-06-03 Sun	100	—	unknown	23:15–03:45 (good, 4.5 h)	87.2° 05:30	4.72	1%	83.8°
2046-06-04 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 05:25	4.69	0%	91.4°
2046-06-05 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 05:25	4.66	2%	99.2°
2046-06-06 Wed	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:20	4.63	6%	106.7°
2046-06-07 Thu	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:15	4.6	12%	113.6°
2046-06-08 Fri	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:10	4.58	21%	119.4°
2046-06-09 Sat	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:05	4.55	31%	123.5°
2046-06-10 Sun	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:05	4.53	42%	125.6°
2046-06-11 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 05:00	4.51	53%	125.1°
2046-06-12 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:55	4.49	65%	122.3°
2046-06-13 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:50	4.48	75%	117.4°
2046-06-14 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:50	4.46	84%	111.0°
2046-06-15 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:45	4.45	92%	103.7°
2046-06-16 Sat	83	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:40	4.44	97%	95.8°
2046-06-17 Sun	74	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:35	4.43	99%	87.9°
2046-06-18 Mon	65	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:30	4.43	100%	80.2°
2046-06-19 Tue	59	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:30	4.42	98%	73.0°
2046-06-20 Wed	57	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:25	4.42	94%	66.5°
2046-06-21 Thu	75	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:20	4.42	88%	61.2°
2046-06-22 Fri	82	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:15	4.43	81%	57.3°
2046-06-23 Sat	90	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.43	73%	54.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-05-25&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.