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: 09-16 (100), 09-17 (100), 09-18 (100), 09-19 (100), 09-20 (100) — by astronomy; check the weather when the night is within four days.

2036-09-16astronomy score per night — click a bar for that night2036-10-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-09-16 Tue	100	—	unknown	21:05–02:15 (good, 5.17 h)	87.1° 20:15	8.45	14%	115.8°
2036-09-17 Wed	100	—	unknown	21:05–02:10 (good, 5.08 h)	87.1° 20:10	8.51	7%	110.4°
2036-09-18 Thu	100	—	unknown	21:00–02:05 (good, 5.08 h)	87.1° 20:05	8.56	2%	103.7°
2036-09-19 Fri	100	—	unknown	21:00–02:00 (good, 5.0 h)	87.1° 20:00	8.61	0%	96.4°
2036-09-20 Sat	100	—	unknown	20:55–02:00 (good, 5.08 h)	87.1° 20:00	8.66	1%	88.8°
2036-09-21 Sun	100	—	unknown	20:55–01:55 (good, 5.0 h)	87.1° 19:55	8.71	5%	81.4°
2036-09-22 Mon	100	—	unknown	20:55–01:50 (good, 4.92 h)	87.1° 19:50	8.76	11%	74.6°
2036-09-23 Tue	100	—	unknown	20:50–01:45 (good, 4.92 h)	87.1° 19:45	8.81	19%	68.7°
2036-09-24 Wed	100	—	unknown	20:50–01:40 (good, 4.83 h)	87.1° 19:45	8.86	27%	64.1°
2036-09-25 Thu	95	—	unknown	20:50–01:40 (good, 4.83 h)	87.1° 19:40	8.91	37%	60.8°
2036-09-26 Fri	89	—	unknown	20:45–01:35 (good, 4.83 h)	87.1° 19:35	8.96	47%	59.1°
2036-09-27 Sat	84	—	unknown	20:45–01:30 (good, 4.75 h)	87.1° 19:30	9.01	56%	58.9°
2036-09-28 Sun	69	—	unknown	20:40–01:05 (good, 4.42 h)	87.1° 19:25	9.06	66%	60.3°
2036-09-29 Mon	60	—	unknown	20:40–00:45 (good, 4.08 h)	87.1° 19:25	9.11	74%	63.0°
2036-09-30 Tue	55	—	unknown	20:40–23:30 (good, 2.83 h)	87.1° 19:20	9.16	82%	66.8°
2036-10-01 Wed	54	—	unknown	20:35–22:55 (good, 2.33 h)	87.1° 19:15	9.21	89%	71.5°
2036-10-02 Thu	54	—	unknown	20:35–22:50 (good, 2.25 h)	87.1° 19:10	9.25	94%	77.0°
2036-10-03 Fri	57	—	unknown	20:35–23:05 (good, 2.5 h)	87.1° 19:05	9.3	98%	83.0°
2036-10-04 Sat	63	—	unknown	20:30–23:25 (good, 2.92 h)	87.1° 19:05	9.35	100%	89.3°
2036-10-05 Sun	70	—	unknown	20:30–23:55 (good, 3.42 h)	87.1° 19:00	9.4	100%	95.7°
2036-10-06 Mon	77	—	unknown	20:30–00:25 (good, 3.92 h)	87.1° 18:55	9.44	98%	102.0°
2036-10-07 Tue	87	—	unknown	20:25–00:30 (good, 4.08 h)	87.1° 18:50	9.49	93%	108.0°
2036-10-08 Wed	100	—	unknown	20:25–00:30 (good, 4.08 h)	87.1° 18:50	9.53	87%	113.2°
2036-10-09 Thu	100	—	unknown	20:25–00:30 (good, 4.08 h)	87.1° 18:45	9.58	79%	117.4°
2036-10-10 Fri	100	—	unknown	20:20–00:30 (good, 4.17 h)	87.1° 18:40	9.63	70%	120.1°
2036-10-11 Sat	100	—	unknown	20:20–00:30 (good, 4.17 h)	87.1° 18:35	9.67	59%	121.1°
2036-10-12 Sun	100	—	unknown	20:20–00:30 (good, 4.17 h)	87.1° 18:30	9.71	48%	120.0°
2036-10-13 Mon	100	—	unknown	20:15–00:25 (good, 4.17 h)	87.1° 18:30	9.76	37%	117.0°
2036-10-14 Tue	100	—	unknown	20:15–00:25 (good, 4.17 h)	87.1° 18:25	9.8	26%	112.2°
2036-10-15 Wed	100	—	unknown	20:15–00:20 (good, 4.08 h)	87.1° 18:20	9.85	17%	106.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-09-16&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.