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: 08-10 (100), 08-11 (100), 08-12 (100), 08-13 (100), 08-14 (100) — by astronomy; check the weather when the night is within four days.

2036-08-02astronomy score per night — click a bar for that night2036-08-31

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-08-02 Sat	96	—	unknown	22:35–04:30 (good, 5.92 h)	71.1° 00:35	5.94	85%	54.1°
2036-08-03 Sun	90	—	unknown	01:40–04:30 (good, 2.83 h)	71.1° 00:30	5.99	91%	47.8°
2036-08-04 Mon	52	—	unknown	22:30–04:30 (marginal, 6.0 h)	71.1° 00:25	6.05	96%	43.3°
2036-08-05 Tue	43	—	unknown	22:25–04:35 (marginal, 6.17 h)	71.1° 00:25	6.1	99%	41.3°
2036-08-06 Wed	43	—	unknown	22:25–04:35 (marginal, 6.17 h)	71.1° 00:20	6.16	100%	42.0°
2036-08-07 Thu	48	—	unknown	22:25–04:35 (marginal, 6.17 h)	71.1° 00:15	6.22	99%	45.3°
2036-08-08 Fri	58	—	unknown	22:20–23:00 (good, 0.67 h)	71.1° 00:10	6.27	97%	50.7°
2036-08-09 Sat	70	—	unknown	22:20–00:30 (good, 2.17 h)	71.1° 00:10	6.33	93%	57.6°
2036-08-10 Sun	100	—	unknown	22:15–02:20 (good, 4.08 h)	71.1° 00:05	6.39	87%	65.6°
2036-08-11 Mon	100	—	unknown	22:15–03:25 (good, 5.17 h)	71.1° 00:00	6.45	80%	74.3°
2036-08-12 Tue	100	—	unknown	22:15–04:25 (good, 6.17 h)	71.1° 23:55	6.5	71%	83.5°
2036-08-13 Wed	100	—	unknown	22:10–04:40 (good, 6.5 h)	71.1° 23:50	6.56	62%	93.0°
2036-08-14 Thu	100	—	unknown	22:10–04:45 (good, 6.58 h)	71.1° 23:50	6.62	51%	102.7°
2036-08-15 Fri	100	—	unknown	22:10–04:45 (good, 6.58 h)	71.1° 23:45	6.68	41%	112.3°
2036-08-16 Sat	100	—	unknown	22:05–04:45 (good, 6.67 h)	71.1° 23:40	6.73	30%	121.6°
2036-08-17 Sun	100	—	unknown	22:05–04:40 (good, 6.58 h)	71.1° 23:35	6.79	20%	129.8°
2036-08-18 Mon	100	—	unknown	22:00–04:40 (good, 6.67 h)	71.1° 23:30	6.85	11%	136.0°
2036-08-19 Tue	100	—	unknown	22:00–04:35 (good, 6.58 h)	71.1° 23:30	6.91	5%	138.8°
2036-08-20 Wed	100	—	unknown	22:00–04:30 (good, 6.5 h)	71.1° 23:25	6.96	1%	137.2°
2036-08-21 Thu	100	—	unknown	21:55–04:25 (good, 6.5 h)	71.1° 23:20	7.02	0%	131.6°
2036-08-22 Fri	100	—	unknown	21:55–04:25 (good, 6.5 h)	71.1° 23:15	7.08	2%	123.2°
2036-08-23 Sat	100	—	unknown	21:50–04:20 (good, 6.5 h)	71.1° 23:15	7.13	7%	113.4°
2036-08-24 Sun	100	—	unknown	21:50–04:15 (good, 6.42 h)	71.1° 23:10	7.19	14%	103.1°
2036-08-25 Mon	100	—	unknown	21:50–04:10 (good, 6.33 h)	71.1° 23:05	7.25	23%	92.6°
2036-08-26 Tue	100	—	unknown	21:45–04:05 (good, 6.33 h)	71.1° 23:00	7.31	33%	82.5°
2036-08-27 Wed	100	—	unknown	21:45–04:05 (good, 6.33 h)	71.1° 22:55	7.36	43%	72.9°
2036-08-28 Thu	100	—	unknown	21:40–04:00 (good, 6.33 h)	71.1° 22:55	7.42	53%	64.0°
2036-08-29 Fri	98	—	unknown	21:40–03:55 (good, 6.25 h)	71.1° 22:50	7.48	63%	56.0°
2036-08-30 Sat	92	—	unknown	21:40–03:50 (good, 6.17 h)	71.1° 22:45	7.53	72%	49.3°
2036-08-31 Sun	86	—	unknown	23:00–03:45 (good, 4.75 h)	71.1° 22:40	7.59	80%	44.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-08-02&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.