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: 07-24 (100), 07-25 (100), 07-26 (100), 07-27 (100), 07-28 (100) — by astronomy; check the weather when the night is within four days.

2035-07-20astronomy score per night — click a bar for that night2035-08-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-07-20 Fri	54	—	unknown	22:55–23:25 (good, 0.5 h)	87.1° 00:05	5.22	100%	60.5°
2035-07-21 Sat	62	—	unknown	22:50–00:45 (good, 1.92 h)	87.1° 00:00	5.26	98%	64.1°
2035-07-22 Sun	72	—	unknown	22:50–02:50 (good, 4.0 h)	87.1° 23:55	5.31	94%	68.9°
2035-07-23 Mon	77	—	unknown	22:50–03:35 (good, 4.75 h)	87.1° 23:55	5.36	89%	74.6°
2035-07-24 Tue	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.1° 23:50	5.41	82%	81.0°
2035-07-25 Wed	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:45	5.46	73%	87.8°
2035-07-26 Thu	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:40	5.52	63%	94.8°
2035-07-27 Fri	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:40	5.57	52%	101.9°
2035-07-28 Sat	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:35	5.62	41%	108.5°
2035-07-29 Sun	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:30	5.67	30%	114.4°
2035-07-30 Mon	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:25	5.73	20%	119.1°
2035-07-31 Tue	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:20	5.78	11%	121.9°
2035-08-01 Wed	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:20	5.84	5%	122.3°
2035-08-02 Thu	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:15	5.89	1%	120.4°
2035-08-03 Fri	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:10	5.95	0%	116.3°
2035-08-04 Sat	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:05	6.0	2%	110.6°
2035-08-05 Sun	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:00	6.06	7%	103.9°
2035-08-06 Mon	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 23:00	6.12	13%	96.8°
2035-08-07 Tue	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.17	22%	89.6°
2035-08-08 Wed	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.1° 22:50	6.23	31%	82.7°
2035-08-09 Thu	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:45	6.29	40%	76.2°
2035-08-10 Fri	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:45	6.34	50%	70.4°
2035-08-11 Sat	100	—	unknown	22:15–04:40 (good, 6.42 h)	87.1° 22:40	6.4	60%	65.5°
2035-08-12 Sun	97	—	unknown	22:15–04:35 (good, 6.33 h)	87.1° 22:35	6.46	69%	61.6°
2035-08-13 Mon	91	—	unknown	22:15–04:30 (good, 6.25 h)	87.1° 22:30	6.52	77%	58.9°
2035-08-14 Tue	85	—	unknown	22:10–04:25 (good, 6.25 h)	87.1° 22:25	6.57	85%	57.6°
2035-08-15 Wed	76	—	unknown	00:00–02:15 (good, 2.25 h)	87.1° 22:25	6.63	91%	57.9°
2035-08-16 Thu	58	—	unknown	22:05–04:50 (marginal, 6.75 h)	87.1° 22:20	6.69	96%	59.7°
2035-08-17 Fri	58	—	unknown	22:05–22:30 (good, 0.42 h)	87.1° 22:15	6.75	99%	63.0°
2035-08-18 Sat	62	—	unknown	22:05–23:35 (good, 1.5 h)	87.1° 22:10	6.8	100%	67.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-07-20&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.