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: 08-29 (100), 08-30 (100), 08-31 (100), 09-01 (100), 09-02 (100) — by astronomy; check the weather when the night is within four days.

2029-08-20astronomy score per night — click a bar for that night2029-09-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-08-20 Mon	75	—	unknown	22:00–02:40 (good, 4.67 h)	87.1° 22:00	6.95	90%	60.4°
2029-08-21 Tue	58	—	unknown	21:55–22:05 (good, 0.17 h)	87.1° 21:55	7.0	95%	60.8°
2029-08-22 Wed	55	—	unknown	21:55–22:05 (good, 0.17 h)	87.1° 21:55	7.06	98%	62.8°
2029-08-23 Thu	56	—	unknown	21:55–22:40 (good, 0.75 h)	87.1° 21:50	7.12	100%	66.2°
2029-08-24 Fri	61	—	unknown	21:50–23:40 (good, 1.83 h)	87.1° 21:45	7.17	99%	70.6°
2029-08-25 Sat	69	—	unknown	21:50–00:45 (good, 2.92 h)	87.1° 21:40	7.23	96%	75.7°
2029-08-26 Sun	76	—	unknown	21:45–01:25 (good, 3.67 h)	87.1° 21:40	7.29	92%	81.3°
2029-08-27 Mon	81	—	unknown	21:45–02:10 (good, 4.42 h)	87.1° 21:35	7.35	86%	87.2°
2029-08-28 Tue	86	—	unknown	21:45–02:55 (good, 5.17 h)	87.1° 21:30	7.4	79%	93.1°
2029-08-29 Wed	100	—	unknown	21:40–03:05 (good, 5.42 h)	87.1° 21:25	7.46	71%	98.8°
2029-08-30 Thu	100	—	unknown	21:40–03:05 (good, 5.42 h)	87.1° 21:20	7.51	62%	104.3°
2029-08-31 Fri	100	—	unknown	21:35–03:05 (good, 5.5 h)	87.1° 21:20	7.57	52%	109.3°
2029-09-01 Sat	100	—	unknown	21:35–03:05 (good, 5.5 h)	87.1° 21:15	7.63	43%	113.7°
2029-09-02 Sun	100	—	unknown	21:35–03:05 (good, 5.5 h)	87.1° 21:10	7.68	33%	117.1°
2029-09-03 Mon	100	—	unknown	21:30–03:05 (good, 5.58 h)	87.1° 21:05	7.74	24%	119.2°
2029-09-04 Tue	100	—	unknown	21:30–03:00 (good, 5.5 h)	87.1° 21:00	7.79	16%	119.8°
2029-09-05 Wed	100	—	unknown	21:25–03:00 (good, 5.58 h)	87.1° 21:00	7.85	8%	118.5°
2029-09-06 Thu	100	—	unknown	21:25–02:55 (good, 5.5 h)	87.1° 20:55	7.9	3%	115.5°
2029-09-07 Fri	100	—	unknown	21:25–02:50 (good, 5.42 h)	87.1° 20:50	7.96	0%	110.7°
2029-09-08 Sat	100	—	unknown	21:20–02:45 (good, 5.42 h)	87.1° 20:45	8.01	0%	104.7°
2029-09-09 Sun	100	—	unknown	21:20–02:40 (good, 5.33 h)	87.1° 20:45	8.07	3%	97.8°
2029-09-10 Mon	100	—	unknown	21:15–02:40 (good, 5.42 h)	87.1° 20:40	8.12	9%	90.4°
2029-09-11 Tue	100	—	unknown	21:15–02:35 (good, 5.33 h)	87.1° 20:35	8.17	17%	83.1°
2029-09-12 Wed	100	—	unknown	21:15–02:30 (good, 5.25 h)	87.1° 20:30	8.23	27%	76.3°
2029-09-13 Thu	100	—	unknown	21:10–02:25 (good, 5.25 h)	87.1° 20:25	8.28	37%	70.2°
2029-09-14 Fri	98	—	unknown	21:10–02:20 (good, 5.17 h)	87.1° 20:25	8.33	48%	65.4°
2029-09-15 Sat	89	—	unknown	21:05–02:20 (good, 5.25 h)	87.1° 20:20	8.39	60%	62.0°
2029-09-16 Sun	81	—	unknown	21:05–02:15 (good, 5.17 h)	87.1° 20:15	8.44	70%	60.3°
2029-09-17 Mon	60	—	unknown	21:05–01:05 (good, 4.0 h)	87.1° 20:10	8.49	79%	60.3°
2029-09-18 Tue	53	—	unknown	21:00–23:10 (good, 2.17 h)	87.1° 20:05	8.54	86%	62.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-08-20&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.