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: 06-30 (100), 07-01 (100), 07-02 (100), 07-03 (100), 07-04 (100) — by astronomy; check the weather when the night is within four days.

2037-06-29astronomy score per night — click a bar for that night2037-07-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-06-29 Mon	65	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:25	4.51	95%	64.1°
2037-06-30 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.52	89%	68.0°
2037-07-01 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.55	83%	72.7°
2037-07-02 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:15	4.57	75%	78.0°
2037-07-03 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:10	4.59	66%	83.6°
2037-07-04 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:05	4.62	57%	89.5°
2037-07-05 Sun	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:00	4.65	47%	95.4°
2037-07-06 Mon	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:00	4.68	38%	101.2°
2037-07-07 Tue	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:55	4.71	28%	106.8°
2037-07-08 Wed	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.74	20%	111.8°
2037-07-09 Thu	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:45	4.78	12%	115.9°
2037-07-10 Fri	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:45	4.81	6%	118.7°
2037-07-11 Sat	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:40	4.85	2%	119.9°
2037-07-12 Sun	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:35	4.89	0%	119.2°
2037-07-13 Mon	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.1° 00:30	4.93	1%	116.4°
2037-07-14 Tue	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:25	4.97	5%	112.0°
2037-07-15 Wed	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:25	5.01	11%	106.2°
2037-07-16 Thu	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:20	5.06	19%	99.5°
2037-07-17 Fri	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:15	5.1	29%	92.4°
2037-07-18 Sat	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:10	5.15	40%	85.3°
2037-07-19 Sun	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:05	5.19	52%	78.5°
2037-07-20 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:05	5.24	63%	72.4°
2037-07-21 Tue	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 00:00	5.29	73%	67.3°
2037-07-22 Wed	99	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.34	82%	63.3°
2037-07-23 Thu	93	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:50	5.39	90%	60.9°
2037-07-24 Fri	65	—	unknown	00:05–04:15 (good, 4.17 h)	87.1° 23:50	5.44	95%	60.1°
2037-07-25 Sat	59	—	unknown	01:50–03:00 (good, 1.17 h)	87.1° 23:45	5.49	98%	60.9°
2037-07-26 Sun	60	—	unknown	22:45–00:00 (good, 1.25 h)	87.1° 23:40	5.54	100%	63.2°
2037-07-27 Mon	66	—	unknown	22:40–02:00 (good, 3.33 h)	87.1° 23:35	5.6	99%	66.7°
2037-07-28 Tue	72	—	unknown	22:40–02:40 (good, 4.0 h)	87.1° 23:30	5.65	97%	71.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-06-29&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.