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: 08-30 (100), 08-31 (100), 09-01 (100), 09-02 (100), 09-03 (100) — by astronomy; check the weather when the night is within four days.

2043-08-30astronomy score per night — click a bar for that night2043-09-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-08-30 Sun	100	—	unknown	21:40–03:20 (good, 5.67 h)	87.1° 21:25	7.49	15%	113.2°
2043-08-31 Mon	100	—	unknown	21:40–03:20 (good, 5.67 h)	87.1° 21:20	7.55	8%	112.2°
2043-09-01 Tue	100	—	unknown	21:35–03:15 (good, 5.67 h)	87.1° 21:15	7.6	3%	109.8°
2043-09-02 Wed	100	—	unknown	21:35–03:10 (good, 5.58 h)	87.1° 21:10	7.66	0%	106.5°
2043-09-03 Thu	100	—	unknown	21:30–03:10 (good, 5.67 h)	87.1° 21:10	7.72	0%	102.3°
2043-09-04 Fri	100	—	unknown	21:30–03:05 (good, 5.58 h)	87.1° 21:05	7.77	2%	97.7°
2043-09-05 Sat	100	—	unknown	21:30–03:00 (good, 5.5 h)	87.1° 21:00	7.83	6%	92.9°
2043-09-06 Sun	100	—	unknown	21:25–02:55 (good, 5.5 h)	87.1° 20:55	7.88	11%	88.0°
2043-09-07 Mon	100	—	unknown	21:25–02:50 (good, 5.42 h)	87.1° 20:55	7.94	18%	83.3°
2043-09-08 Tue	100	—	unknown	21:20–02:50 (good, 5.5 h)	87.1° 20:50	7.99	26%	78.9°
2043-09-09 Wed	100	—	unknown	21:20–02:45 (good, 5.42 h)	87.1° 20:45	8.05	35%	75.0°
2043-09-10 Thu	100	—	unknown	21:20–02:40 (good, 5.33 h)	87.1° 20:40	8.1	44%	71.7°
2043-09-11 Fri	99	—	unknown	21:15–02:35 (good, 5.33 h)	87.1° 20:35	8.15	54%	69.1°
2043-09-12 Sat	92	—	unknown	21:15–02:30 (good, 5.25 h)	87.1° 20:35	8.21	63%	67.4°
2043-09-13 Sun	85	—	unknown	21:10–02:30 (good, 5.33 h)	87.1° 20:30	8.26	72%	66.8°
2043-09-14 Mon	70	—	unknown	21:10–01:55 (good, 4.75 h)	87.1° 20:25	8.31	81%	67.3°
2043-09-15 Tue	62	—	unknown	21:10–00:45 (good, 3.58 h)	87.1° 20:20	8.37	88%	69.0°
2043-09-16 Wed	59	—	unknown	21:05–23:45 (good, 2.67 h)	87.1° 20:15	8.42	94%	71.8°
2043-09-17 Thu	59	—	unknown	21:05–23:30 (good, 2.42 h)	87.1° 20:15	8.47	98%	75.8°
2043-09-18 Fri	62	—	unknown	21:00–23:40 (good, 2.67 h)	87.1° 20:10	8.52	100%	80.5°
2043-09-19 Sat	68	—	unknown	21:00–00:05 (good, 3.08 h)	87.1° 20:05	8.57	99%	85.9°
2043-09-20 Sun	77	—	unknown	21:00–00:40 (good, 3.67 h)	87.1° 20:00	8.63	95%	91.6°
2043-09-21 Mon	85	—	unknown	20:55–01:20 (good, 4.42 h)	87.1° 20:00	8.68	89%	97.3°
2043-09-22 Tue	100	—	unknown	20:55–01:30 (good, 4.58 h)	87.1° 19:55	8.73	81%	102.5°
2043-09-23 Wed	100	—	unknown	20:55–01:35 (good, 4.67 h)	87.1° 19:50	8.78	71%	107.0°
2043-09-24 Thu	100	—	unknown	20:50–01:35 (good, 4.75 h)	87.1° 19:45	8.83	60%	110.4°
2043-09-25 Fri	100	—	unknown	20:50–01:35 (good, 4.75 h)	87.1° 19:40	8.88	48%	112.5°
2043-09-26 Sat	100	—	unknown	20:45–01:35 (good, 4.83 h)	87.1° 19:40	8.93	37%	113.2°
2043-09-27 Sun	100	—	unknown	20:45–01:35 (good, 4.83 h)	87.1° 19:35	8.98	27%	112.5°
2043-09-28 Mon	100	—	unknown	20:45–01:30 (good, 4.75 h)	87.1° 19:30	9.03	18%	110.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-08-30&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.