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: 08-23 (100), 08-24 (100), 08-25 (100), 08-26 (100), 08-27 (100) — by astronomy; check the weather when the night is within four days.

2044-08-23astronomy score per night — click a bar for that night2044-09-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-08-23 Tue	100	—	unknown	21:50–03:50 (good, 6.0 h)	87.1° 21:50	7.14	1%	104.7°
2044-08-24 Wed	100	—	unknown	21:50–03:45 (good, 5.92 h)	87.1° 21:45	7.2	5%	99.7°
2044-08-25 Thu	100	—	unknown	21:50–03:40 (good, 5.83 h)	87.1° 21:40	7.25	10%	94.3°
2044-08-26 Fri	100	—	unknown	21:45–03:35 (good, 5.83 h)	87.1° 21:35	7.31	18%	88.9°
2044-08-27 Sat	100	—	unknown	21:45–03:30 (good, 5.75 h)	87.1° 21:35	7.37	27%	83.7°
2044-08-28 Sun	100	—	unknown	21:40–03:30 (good, 5.83 h)	87.1° 21:30	7.42	36%	78.9°
2044-08-29 Mon	100	—	unknown	21:40–03:25 (good, 5.75 h)	87.1° 21:25	7.48	46%	74.7°
2044-08-30 Tue	100	—	unknown	21:40–03:20 (good, 5.67 h)	87.1° 21:20	7.54	55%	71.2°
2044-08-31 Wed	97	—	unknown	21:35–03:15 (good, 5.67 h)	87.1° 21:15	7.59	64%	68.5°
2044-09-01 Thu	90	—	unknown	21:35–03:15 (good, 5.67 h)	87.1° 21:15	7.65	73%	66.7°
2044-09-02 Fri	82	—	unknown	21:30–03:10 (good, 5.67 h)	87.1° 21:10	7.7	81%	65.9°
2044-09-03 Sat	67	—	unknown	21:30–02:00 (good, 4.5 h)	87.1° 21:05	7.76	88%	66.3°
2044-09-04 Sun	62	—	unknown	21:30–00:30 (good, 3.0 h)	87.1° 21:00	7.81	94%	67.8°
2044-09-05 Mon	60	—	unknown	21:25–23:55 (good, 2.5 h)	87.1° 21:00	7.87	98%	70.3°
2044-09-06 Tue	60	—	unknown	21:25–23:50 (good, 2.42 h)	87.1° 20:55	7.92	100%	73.8°
2044-09-07 Wed	64	—	unknown	21:20–00:00 (good, 2.67 h)	87.1° 20:50	7.98	100%	78.0°
2044-09-08 Thu	71	—	unknown	21:20–00:30 (good, 3.17 h)	87.1° 20:45	8.03	98%	82.9°
2044-09-09 Fri	79	—	unknown	21:20–01:05 (good, 3.75 h)	87.1° 20:40	8.09	94%	88.2°
2044-09-10 Sat	84	—	unknown	21:15–01:45 (good, 4.5 h)	87.1° 20:40	8.14	87%	93.7°
2044-09-11 Sun	100	—	unknown	21:15–02:10 (good, 4.92 h)	87.1° 20:35	8.19	79%	99.0°
2044-09-12 Mon	100	—	unknown	21:10–02:10 (good, 5.0 h)	87.1° 20:30	8.25	69%	104.0°
2044-09-13 Tue	100	—	unknown	21:10–02:15 (good, 5.08 h)	87.1° 20:25	8.3	58%	108.3°
2044-09-14 Wed	100	—	unknown	21:10–02:15 (good, 5.08 h)	87.1° 20:20	8.35	47%	111.6°
2044-09-15 Thu	100	—	unknown	21:05–02:15 (good, 5.17 h)	87.1° 20:20	8.41	36%	113.6°
2044-09-16 Fri	100	—	unknown	21:05–02:10 (good, 5.08 h)	87.1° 20:15	8.46	25%	114.0°
2044-09-17 Sat	100	—	unknown	21:05–02:10 (good, 5.08 h)	87.1° 20:10	8.51	16%	112.9°
2044-09-18 Sun	100	—	unknown	21:00–02:05 (good, 5.08 h)	87.1° 20:05	8.56	8%	110.3°
2044-09-19 Mon	100	—	unknown	21:00–02:00 (good, 5.0 h)	87.1° 20:05	8.61	3%	106.5°
2044-09-20 Tue	100	—	unknown	20:55–02:00 (good, 5.08 h)	87.1° 20:00	8.67	0%	101.8°
2044-09-21 Wed	100	—	unknown	20:55–01:55 (good, 5.0 h)	87.1° 19:55	8.72	0%	96.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-08-23&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.