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: 07-19 (100), 07-20 (100), 07-21 (100), 07-22 (100), 07-23 (100) — by astronomy; check the weather when the night is within four days.

2038-07-18astronomy score per night — click a bar for that night2038-08-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-07-18 Sun	76	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 00:10	5.14	93%	72.7°
2038-07-19 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:10	5.18	87%	77.9°
2038-07-20 Tue	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:05	5.23	80%	83.5°
2038-07-21 Wed	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 00:00	5.28	71%	89.2°
2038-07-22 Thu	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.33	62%	94.9°
2038-07-23 Fri	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:50	5.38	53%	100.3°
2038-07-24 Sat	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:50	5.43	43%	105.4°
2038-07-25 Sun	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:45	5.48	34%	109.9°
2038-07-26 Mon	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:40	5.53	25%	113.7°
2038-07-27 Tue	100	—	unknown	22:45–04:20 (good, 5.58 h)	87.1° 23:35	5.58	17%	116.5°
2038-07-28 Wed	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:35	5.64	10%	118.0°
2038-07-29 Thu	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:30	5.69	5%	118.1°
2038-07-30 Fri	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:25	5.74	1%	116.6°
2038-07-31 Sat	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:20	5.8	0%	113.6°
2038-08-01 Sun	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:15	5.85	1%	109.2°
2038-08-02 Mon	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:15	5.91	5%	103.8°
2038-08-03 Tue	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:10	5.96	11%	97.5°
2038-08-04 Wed	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:05	6.02	19%	90.9°
2038-08-05 Thu	100	—	unknown	22:25–04:30 (good, 6.08 h)	87.1° 23:00	6.08	29%	84.1°
2038-08-06 Fri	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.13	40%	77.7°
2038-08-07 Sat	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.19	51%	72.0°
2038-08-08 Sun	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.1° 22:50	6.25	62%	67.2°
2038-08-09 Mon	98	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:45	6.3	73%	63.8°
2038-08-10 Tue	91	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:40	6.36	82%	62.0°
2038-08-11 Wed	84	—	unknown	22:15–04:35 (good, 6.33 h)	87.1° 22:40	6.42	90%	62.0°
2038-08-12 Thu	64	—	unknown	22:15–02:30 (good, 4.25 h)	87.1° 22:35	6.47	95%	63.6°
2038-08-13 Fri	65	—	unknown	22:15–01:35 (good, 3.33 h)	87.1° 22:30	6.53	99%	66.7°
2038-08-14 Sat	68	—	unknown	22:10–01:30 (good, 3.33 h)	87.1° 22:25	6.59	100%	71.0°
2038-08-15 Sun	72	—	unknown	22:10–01:50 (good, 3.67 h)	87.1° 22:20	6.65	99%	76.0°
2038-08-16 Mon	77	—	unknown	22:05–02:20 (good, 4.25 h)	87.1° 22:20	6.7	96%	81.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-07-18&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.