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 HD 189733: 06-16 (100), 06-17 (100), 06-18 (100), 06-19 (100), 06-20 (100) — by astronomy; check the weather when the night is within four days.

2036-06-14astronomy score per night — click a bar for that night2036-07-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-06-14 Sat	92	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:50	4.46	70%	47.7°
2036-06-15 Sun	96	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:45	4.45	61%	54.0°
2036-06-16 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:40	4.44	51%	61.6°
2036-06-17 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:35	4.43	41%	70.2°
2036-06-18 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:30	4.43	31%	79.5°
2036-06-19 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:30	4.42	22%	89.3°
2036-06-20 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:25	4.42	14%	99.5°
2036-06-21 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:20	4.42	7%	109.8°
2036-06-22 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:15	4.43	2%	119.7°
2036-06-23 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:10	4.43	0%	128.6°
2036-06-24 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:10	4.44	1%	135.3°
2036-06-25 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:05	4.45	5%	138.7°
2036-06-26 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:00	4.46	11%	137.7°
2036-06-27 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 02:55	4.48	20%	132.8°
2036-06-28 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 02:55	4.49	30%	125.2°
2036-06-29 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:50	4.51	41%	116.2°
2036-06-30 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:45	4.53	52%	106.5°
2036-07-01 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:40	4.55	63%	96.6°
2036-07-02 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:35	4.57	72%	86.8°
2036-07-03 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:35	4.6	81%	77.3°
2036-07-04 Fri	100	—	unknown	23:35–03:45 (good, 4.17 h)	71.1° 02:30	4.63	88%	68.2°
2036-07-05 Sat	63	—	unknown	00:45–03:50 (good, 3.08 h)	71.1° 02:25	4.65	94%	59.8°
2036-07-06 Sun	50	—	unknown	03:10–03:50 (good, 0.67 h)	71.1° 02:20	4.69	98%	52.4°
2036-07-07 Mon	42	—	unknown	23:05–03:50 (marginal, 4.75 h)	71.1° 02:15	4.72	100%	46.5°
2036-07-08 Tue	36	—	unknown	23:05–03:50 (marginal, 4.75 h)	71.1° 02:15	4.75	100%	42.6°
2036-07-09 Wed	38	—	unknown	23:05–03:55 (marginal, 4.83 h)	71.1° 02:10	4.79	98%	41.2°
2036-07-10 Thu	44	—	unknown	23:05–03:55 (marginal, 4.83 h)	71.1° 02:05	4.82	95%	42.6°
2036-07-11 Fri	55	—	unknown	23:05–00:45 (good, 1.67 h)	71.1° 02:00	4.86	90%	46.5°
2036-07-12 Sat	93	—	unknown	23:05–02:40 (good, 3.58 h)	71.1° 02:00	4.9	83%	52.3°
2036-07-13 Sun	99	—	unknown	23:00–04:00 (good, 5.0 h)	71.1° 01:55	4.94	75%	59.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-06-14&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.