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: 07-14 (100), 07-15 (100), 07-16 (100), 07-17 (100), 07-18 (100) — by astronomy; check the weather when the night is within four days.

2036-07-07astronomy score per night — click a bar for that night2036-08-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2036-07-14 Mon	100	—	unknown	23:00–04:00 (good, 5.0 h)	71.1° 01:50	4.98	66%	67.7°
2036-07-15 Tue	100	—	unknown	23:00–04:00 (good, 5.0 h)	71.1° 01:45	5.02	57%	76.6°
2036-07-16 Wed	100	—	unknown	23:00–04:00 (good, 5.0 h)	71.1° 01:40	5.07	47%	86.0°
2036-07-17 Thu	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:40	5.11	36%	95.9°
2036-07-18 Fri	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:35	5.16	26%	105.8°
2036-07-19 Sat	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:30	5.2	17%	115.7°
2036-07-20 Sun	100	—	unknown	22:55–04:10 (good, 5.25 h)	71.1° 01:25	5.25	9%	125.0°
2036-07-21 Mon	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:20	5.3	3%	132.7°
2036-07-22 Tue	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:20	5.35	0%	137.7°
2036-07-23 Wed	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:15	5.4	0%	138.6°
2036-07-24 Thu	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:10	5.45	3%	135.1°
2036-07-25 Fri	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:05	5.5	9%	128.1°
2036-07-26 Sat	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:05	5.56	17%	119.2°
2036-07-27 Sun	100	—	unknown	22:40–04:20 (good, 5.67 h)	71.1° 01:00	5.61	27%	109.4°
2036-07-28 Mon	100	—	unknown	22:40–04:20 (good, 5.67 h)	71.1° 00:55	5.66	37%	99.3°
2036-07-29 Tue	100	—	unknown	22:40–04:20 (good, 5.67 h)	71.1° 00:50	5.72	48%	89.2°
2036-07-30 Wed	100	—	unknown	22:35–04:25 (good, 5.83 h)	71.1° 00:45	5.77	58%	79.5°
2036-07-31 Thu	100	—	unknown	22:35–04:25 (good, 5.83 h)	71.1° 00:45	5.82	68%	70.3°
2036-08-01 Fri	100	—	unknown	22:35–04:25 (good, 5.83 h)	71.1° 00:40	5.88	77%	61.7°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-07-07&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.