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: 04-23 (100), 04-24 (100), 04-25 (100), 04-26 (100), 04-27 (100) — by astronomy; check the weather when the night is within four days.

2033-04-19astronomy score per night — click a bar for that night2033-05-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-04-19 Tue	70	—	unknown	00:10–04:55 (good, 4.75 h)	87.1° 06:05	7.04	76%	58.2°
2033-04-20 Wed	85	—	unknown	00:05–04:50 (good, 4.75 h)	87.1° 06:00	6.99	67%	56.6°
2033-04-21 Thu	91	—	unknown	00:05–04:50 (good, 4.75 h)	87.1° 05:55	6.93	56%	56.9°
2033-04-22 Fri	97	—	unknown	00:00–04:50 (good, 4.83 h)	87.1° 05:55	6.87	45%	59.3°
2033-04-23 Sat	100	—	unknown	23:55–04:45 (good, 4.83 h)	87.1° 05:50	6.81	34%	63.6°
2033-04-24 Sun	100	—	unknown	23:50–04:45 (good, 4.92 h)	87.1° 05:45	6.75	24%	69.6°
2033-04-25 Mon	100	—	unknown	23:45–04:40 (good, 4.92 h)	87.1° 05:40	6.69	14%	76.8°
2033-04-26 Tue	100	—	unknown	23:45–04:40 (good, 4.92 h)	87.1° 05:35	6.64	7%	84.7°
2033-04-27 Wed	100	—	unknown	23:40–04:40 (good, 5.0 h)	87.1° 05:35	6.58	2%	93.0°
2033-04-28 Thu	100	—	unknown	23:35–04:35 (good, 5.0 h)	87.1° 05:30	6.52	0%	101.0°
2033-04-29 Fri	100	—	unknown	23:30–04:35 (good, 5.08 h)	87.1° 05:25	6.46	1%	108.5°
2033-04-30 Sat	100	—	unknown	23:25–04:35 (good, 5.17 h)	87.1° 05:20	6.4	5%	114.8°
2033-05-01 Sun	100	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:20	6.35	11%	119.6°
2033-05-02 Mon	100	—	unknown	23:20–04:30 (good, 5.17 h)	87.1° 05:15	6.29	18%	122.6°
2033-05-03 Tue	100	—	unknown	23:20–04:25 (good, 5.08 h)	87.1° 05:10	6.23	27%	123.5°
2033-05-04 Wed	100	—	unknown	23:15–04:25 (good, 5.17 h)	87.1° 05:05	6.17	37%	122.5°
2033-05-05 Thu	100	—	unknown	23:15–04:25 (good, 5.17 h)	87.1° 05:00	6.12	46%	119.9°
2033-05-06 Fri	100	—	unknown	23:10–04:20 (good, 5.17 h)	87.1° 05:00	6.06	56%	115.9°
2033-05-07 Sat	100	—	unknown	23:15–04:20 (good, 5.08 h)	87.1° 04:55	6.0	66%	110.9°
2033-05-08 Sun	100	—	unknown	23:15–04:20 (good, 5.08 h)	87.1° 04:50	5.95	74%	105.3°
2033-05-09 Mon	100	—	unknown	23:15–04:15 (good, 5.0 h)	87.1° 04:45	5.89	82%	99.1°
2033-05-10 Tue	84	—	unknown	23:30–04:15 (good, 4.75 h)	87.1° 04:40	5.83	89%	92.7°
2033-05-11 Wed	79	—	unknown	00:10–04:15 (good, 4.08 h)	87.1° 04:40	5.78	94%	86.1°
2033-05-12 Thu	71	—	unknown	00:50–04:10 (good, 3.33 h)	87.1° 04:35	5.72	98%	79.5°
2033-05-13 Fri	63	—	unknown	01:25–04:10 (good, 2.75 h)	87.1° 04:30	5.67	100%	73.2°
2033-05-14 Sat	57	—	unknown	02:10–04:10 (good, 2.0 h)	87.1° 04:25	5.62	100%	67.5°
2033-05-15 Sun	53	—	unknown	04:00–04:05 (good, 0.08 h)	87.1° 04:25	5.56	98%	62.6°
2033-05-16 Mon	56	—	unknown	01:25–02:05 (good, 0.67 h)	87.1° 04:20	5.51	94%	58.9°
2033-05-17 Tue	84	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:15	5.46	87%	56.9°
2033-05-18 Wed	89	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:10	5.41	80%	56.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-04-19&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.