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 Vega: 05-09 (100), 05-10 (100), 05-11 (100), 05-12 (100), 05-13 (100) — by astronomy; check the weather when the night is within four days.

2046-05-09astronomy score per night — click a bar for that night2046-06-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-05-09 Wed	100	—	unknown	22:55–04:15 (good, 5.33 h)	87.1° 04:45	5.9	15%	115.1°
2046-05-10 Thu	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.1° 04:45	5.84	24%	116.6°
2046-05-11 Fri	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.1° 04:40	5.79	33%	116.5°
2046-05-12 Sat	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 04:35	5.73	44%	114.8°
2046-05-13 Sun	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 04:30	5.68	56%	111.5°
2046-05-14 Mon	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 04:30	5.62	67%	107.0°
2046-05-15 Tue	100	—	unknown	22:50–04:05 (good, 5.25 h)	87.1° 04:25	5.57	77%	101.4°
2046-05-16 Wed	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 04:20	5.52	86%	95.2°
2046-05-17 Thu	81	—	unknown	23:15–04:05 (good, 4.83 h)	87.1° 04:15	5.46	93%	88.6°
2046-05-18 Fri	76	—	unknown	23:45–04:00 (good, 4.25 h)	87.1° 04:10	5.41	98%	82.2°
2046-05-19 Sat	71	—	unknown	00:00–04:00 (good, 4.0 h)	87.1° 04:10	5.36	100%	76.3°
2046-05-20 Sun	66	—	unknown	23:50–04:00 (good, 4.17 h)	87.1° 04:05	5.31	99%	71.1°
2046-05-21 Mon	81	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:00	5.26	96%	67.1°
2046-05-22 Tue	87	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:55	5.21	91%	64.5°
2046-05-23 Wed	93	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:50	5.17	84%	63.2°
2046-05-24 Thu	97	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:50	5.12	76%	63.5°
2046-05-25 Fri	100	—	unknown	22:50–03:55 (good, 5.08 h)	87.1° 03:45	5.07	67%	65.0°
2046-05-26 Sat	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.03	57%	67.7°
2046-05-27 Sun	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:35	4.99	48%	71.2°
2046-05-28 Mon	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:35	4.94	39%	75.5°
2046-05-29 Tue	100	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 03:30	4.9	30%	80.4°
2046-05-30 Wed	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:25	4.86	21%	85.6°
2046-05-31 Thu	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.83	14%	91.0°
2046-06-01 Fri	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:15	4.79	8%	96.6°
2046-06-02 Sat	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:15	4.75	3%	101.9°
2046-06-03 Sun	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.72	1%	106.9°
2046-06-04 Mon	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:05	4.69	0%	111.2°
2046-06-05 Tue	100	—	unknown	23:00–03:40 (good, 4.67 h)	87.1° 03:00	4.66	2%	114.5°
2046-06-06 Wed	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:55	4.63	6%	116.5°
2046-06-07 Thu	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:55	4.6	12%	116.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-05-09&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.