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: 09-22 (100), 09-23 (100), 09-24 (100), 09-25 (100), 09-26 (100) — by astronomy; check the weather when the night is within four days.

2043-09-22astronomy score per night — click a bar for that night2043-10-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2043-09-29 Tue	100	—	unknown	20:40–01:25 (good, 4.75 h)	87.1° 19:25	9.08	10%	107.5°
2043-09-30 Wed	100	—	unknown	20:40–01:20 (good, 4.67 h)	87.1° 19:20	9.13	5%	103.6°
2043-10-01 Thu	100	—	unknown	20:40–01:20 (good, 4.67 h)	87.1° 19:20	9.17	2%	99.2°
2043-10-02 Fri	100	—	unknown	20:35–01:15 (good, 4.67 h)	87.1° 19:15	9.22	0%	94.4°
2043-10-03 Sat	100	—	unknown	20:35–01:10 (good, 4.58 h)	87.1° 19:10	9.27	1%	89.6°
2043-10-04 Sun	100	—	unknown	20:35–01:05 (good, 4.5 h)	87.1° 19:05	9.32	3%	84.8°
2043-10-05 Mon	100	—	unknown	20:30–01:00 (good, 4.5 h)	87.1° 19:05	9.36	7%	80.3°
2043-10-06 Tue	100	—	unknown	20:30–01:00 (good, 4.5 h)	87.1° 19:00	9.41	13%	76.2°
2043-10-07 Wed	100	—	unknown	20:30–00:55 (good, 4.42 h)	87.1° 18:55	9.46	20%	72.6°
2043-10-08 Thu	100	—	unknown	20:25–00:50 (good, 4.42 h)	87.1° 18:50	9.5	28%	69.8°
2043-10-09 Fri	95	—	unknown	20:25–00:45 (good, 4.33 h)	87.1° 18:45	9.55	37%	67.8°
2043-10-10 Sat	88	—	unknown	20:25–00:40 (good, 4.25 h)	87.1° 18:45	9.59	46%	66.8°
2043-10-11 Sun	75	—	unknown	20:20–00:40 (good, 4.33 h)	87.1° 18:40	9.64	56%	66.9°
2043-10-12 Mon	64	—	unknown	20:20–00:10 (good, 3.83 h)	87.1° 18:35	9.68	66%	68.1°
2043-10-13 Tue	57	—	unknown	20:20–23:45 (good, 3.42 h)	87.1° 18:30	9.73	75%	70.5°
2043-10-14 Wed	52	—	unknown	20:15–22:45 (good, 2.5 h)	87.1° 18:25	9.77	84%	73.9°
2043-10-15 Thu	50	—	unknown	20:15–22:15 (good, 2.0 h)	87.1° 18:25	9.82	91%	78.3°
2043-10-16 Fri	50	—	unknown	20:15–22:15 (good, 2.0 h)	87.1° 18:20	9.86	96%	83.5°
2043-10-17 Sat	54	—	unknown	20:10–22:30 (good, 2.33 h)	87.1° 18:15	9.9	100%	89.2°
2043-10-18 Sun	59	—	unknown	20:10–23:00 (good, 2.83 h)	87.1° 18:10	9.94	100%	95.0°
2043-10-19 Mon	67	—	unknown	20:10–23:35 (good, 3.42 h)	87.1° 18:05	9.99	97%	100.6°
2043-10-20 Tue	74	—	unknown	20:10–23:40 (good, 3.5 h)	87.1° 18:05	10.03	91%	105.6°
2043-10-21 Wed	91	—	unknown	20:05–23:45 (good, 3.67 h)	87.1° 18:00	10.07	84%	109.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-09-22&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.