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: 08-20 (100), 08-21 (100), 08-22 (100), 08-23 (100), 08-24 (100) — by astronomy; check the weather when the night is within four days.

2033-08-20astronomy score per night — click a bar for that night2033-09-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-08-20 Sat	100	—	unknown	22:00–04:00 (good, 6.0 h)	87.1° 22:00	6.95	16%	123.4°
2033-08-21 Sun	100	—	unknown	21:55–03:55 (good, 6.0 h)	87.1° 21:55	7.0	9%	122.8°
2033-08-22 Mon	100	—	unknown	21:55–03:55 (good, 6.0 h)	87.1° 21:55	7.06	4%	120.6°
2033-08-23 Tue	100	—	unknown	21:55–03:50 (good, 5.92 h)	87.1° 21:50	7.12	1%	116.8°
2033-08-24 Wed	100	—	unknown	21:50–03:45 (good, 5.92 h)	87.1° 21:45	7.18	0%	111.9°
2033-08-25 Thu	100	—	unknown	21:50–03:40 (good, 5.83 h)	87.1° 21:40	7.23	1%	106.3°
2033-08-26 Fri	100	—	unknown	21:45–03:35 (good, 5.83 h)	87.1° 21:40	7.29	4%	100.1°
2033-08-27 Sat	100	—	unknown	21:45–03:35 (good, 5.83 h)	87.1° 21:35	7.35	8%	93.7°
2033-08-28 Sun	100	—	unknown	21:45–03:30 (good, 5.75 h)	87.1° 21:30	7.4	14%	87.2°
2033-08-29 Mon	100	—	unknown	21:40–03:25 (good, 5.75 h)	87.1° 21:25	7.46	21%	80.7°
2033-08-30 Tue	100	—	unknown	21:40–03:20 (good, 5.67 h)	87.1° 21:20	7.52	30%	74.6°
2033-08-31 Wed	100	—	unknown	21:35–03:15 (good, 5.67 h)	87.1° 21:20	7.57	39%	68.8°
2033-09-01 Thu	100	—	unknown	21:35–03:15 (good, 5.67 h)	87.1° 21:15	7.63	48%	63.8°
2033-09-02 Fri	94	—	unknown	21:35–03:10 (good, 5.58 h)	87.1° 21:10	7.68	58%	59.8°
2033-09-03 Sat	87	—	unknown	21:30–03:05 (good, 5.58 h)	87.1° 21:05	7.74	68%	57.3°
2033-09-04 Sun	79	—	unknown	21:30–03:00 (good, 5.5 h)	87.1° 21:00	7.79	78%	56.5°
2033-09-05 Mon	56	—	unknown	21:25–00:05 (good, 2.67 h)	87.1° 21:00	7.85	86%	57.8°
2033-09-06 Tue	51	—	unknown	21:25–03:20 (marginal, 5.92 h)	87.1° 20:55	7.9	93%	61.3°
2033-09-07 Wed	51	—	unknown	21:25–22:05 (good, 0.67 h)	87.1° 20:50	7.96	98%	66.7°
2033-09-08 Thu	57	—	unknown	21:20–23:30 (good, 2.17 h)	87.1° 20:45	8.01	100%	73.5°
2033-09-09 Fri	67	—	unknown	21:20–00:15 (good, 2.92 h)	87.1° 20:45	8.07	99%	81.4°
2033-09-10 Sat	80	—	unknown	21:15–01:10 (good, 3.92 h)	87.1° 20:40	8.12	95%	89.7°
2033-09-11 Sun	86	—	unknown	21:15–02:05 (good, 4.83 h)	87.1° 20:35	8.18	88%	97.9°
2033-09-12 Mon	100	—	unknown	21:15–02:10 (good, 4.92 h)	87.1° 20:30	8.23	80%	105.6°
2033-09-13 Tue	100	—	unknown	21:10–02:15 (good, 5.08 h)	87.1° 20:25	8.28	70%	112.3°
2033-09-14 Wed	100	—	unknown	21:10–02:15 (good, 5.08 h)	87.1° 20:25	8.34	59%	117.8°
2033-09-15 Thu	100	—	unknown	21:05–02:15 (good, 5.17 h)	87.1° 20:20	8.39	48%	121.5°
2033-09-16 Fri	100	—	unknown	21:05–02:10 (good, 5.08 h)	87.1° 20:15	8.44	37%	123.4°
2033-09-17 Sat	100	—	unknown	21:05–02:10 (good, 5.08 h)	87.1° 20:10	8.49	28%	123.3°
2033-09-18 Sun	100	—	unknown	21:00–02:05 (good, 5.08 h)	87.1° 20:05	8.54	19%	121.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-08-20&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.