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: 04-28 (100), 04-29 (100), 04-30 (100), 05-01 (100), 05-02 (100) — by astronomy; check the weather when the night is within four days.

2036-04-28astronomy score per night — click a bar for that night2036-05-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-04-28 Mon	100	—	unknown	23:35–04:35 (good, 5.0 h)	87.1° 05:30	6.5	8%	117.9°
2036-04-29 Tue	100	—	unknown	23:30–04:35 (good, 5.08 h)	87.1° 05:25	6.45	15%	120.7°
2036-04-30 Wed	100	—	unknown	23:30–04:30 (good, 5.0 h)	87.1° 05:20	6.39	25%	121.5°
2036-05-01 Thu	100	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:15	6.33	35%	120.2°
2036-05-02 Fri	100	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:15	6.27	46%	116.9°
2036-05-03 Sat	100	—	unknown	23:25–04:25 (good, 5.0 h)	87.1° 05:10	6.21	58%	112.0°
2036-05-04 Sun	100	—	unknown	23:25–04:25 (good, 5.0 h)	87.1° 05:05	6.16	69%	105.9°
2036-05-05 Mon	100	—	unknown	23:30–04:25 (good, 4.92 h)	87.1° 05:00	6.1	78%	99.2°
2036-05-06 Tue	83	—	unknown	23:50–04:20 (good, 4.5 h)	87.1° 04:55	6.04	87%	92.1°
2036-05-07 Wed	77	—	unknown	00:40–04:20 (good, 3.67 h)	87.1° 04:55	5.99	93%	85.0°
2036-05-08 Thu	67	—	unknown	01:25–04:20 (good, 2.92 h)	87.1° 04:50	5.93	98%	78.2°
2036-05-09 Fri	59	—	unknown	02:00–04:15 (good, 2.25 h)	87.1° 04:45	5.87	100%	72.0°
2036-05-10 Sat	54	—	unknown	03:15–04:15 (good, 1.0 h)	87.1° 04:40	5.82	99%	66.7°
2036-05-11 Sun	53	—	unknown	22:25–04:55 (marginal, 6.5 h)	87.1° 04:40	5.76	97%	62.6°
2036-05-12 Mon	56	—	unknown	01:30–02:50 (good, 1.33 h)	87.1° 04:35	5.71	93%	59.8°
2036-05-13 Tue	83	—	unknown	22:35–04:10 (good, 5.58 h)	87.1° 04:30	5.65	87%	58.6°
2036-05-14 Wed	89	—	unknown	22:30–04:10 (good, 5.67 h)	87.1° 04:25	5.6	80%	58.9°
2036-05-15 Thu	95	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:20	5.55	72%	60.8°
2036-05-16 Fri	100	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:20	5.49	63%	63.9°
2036-05-17 Sat	100	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:15	5.44	54%	68.1°
2036-05-18 Sun	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:10	5.39	45%	73.2°
2036-05-19 Mon	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:05	5.34	35%	79.0°
2036-05-20 Tue	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:00	5.29	26%	85.3°
2036-05-21 Wed	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 04:00	5.24	18%	91.9°
2036-05-22 Thu	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:55	5.19	10%	98.6°
2036-05-23 Fri	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:50	5.15	5%	105.2°
2036-05-24 Sat	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:45	5.1	1%	111.3°
2036-05-25 Sun	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.06	0%	116.3°
2036-05-26 Mon	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.01	2%	119.9°
2036-05-27 Tue	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:35	4.97	6%	121.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-04-28&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.