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: 04-05 (100), 04-06 (100), 04-07 (100), 04-08 (100), 04-09 (100) — by astronomy; check the weather when the night is within four days.

2038-04-05astronomy score per night — click a bar for that night2038-05-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-04-05 Mon	100	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 07:00	7.86	2%	101.0°
2038-04-06 Tue	100	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 06:55	7.8	5%	106.1°
2038-04-07 Wed	100	—	unknown	01:00–05:20 (good, 4.33 h)	87.1° 06:55	7.74	9%	110.6°
2038-04-08 Thu	100	—	unknown	00:55–05:15 (good, 4.33 h)	87.1° 06:50	7.69	16%	114.3°
2038-04-09 Fri	100	—	unknown	00:50–05:15 (good, 4.42 h)	87.1° 06:45	7.63	23%	117.0°
2038-04-10 Sat	100	—	unknown	00:50–05:10 (good, 4.33 h)	87.1° 06:40	7.57	32%	118.4°
2038-04-11 Sun	100	—	unknown	00:50–05:10 (good, 4.33 h)	87.1° 06:35	7.52	42%	118.4°
2038-04-12 Mon	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:35	7.46	52%	116.8°
2038-04-13 Tue	100	—	unknown	00:45–05:05 (good, 4.33 h)	87.1° 06:30	7.4	62%	113.7°
2038-04-14 Wed	100	—	unknown	00:45–05:05 (good, 4.33 h)	87.1° 06:25	7.35	73%	109.2°
2038-04-15 Thu	88	—	unknown	00:50–05:00 (good, 4.17 h)	87.1° 06:20	7.29	82%	103.5°
2038-04-16 Fri	78	—	unknown	01:00–05:00 (good, 4.0 h)	87.1° 06:20	7.23	90%	96.9°
2038-04-17 Sat	68	—	unknown	01:45–05:00 (good, 3.25 h)	87.1° 06:15	7.17	96%	89.8°
2038-04-18 Sun	59	—	unknown	02:30–04:55 (good, 2.42 h)	87.1° 06:10	7.11	99%	82.6°
2038-04-19 Mon	52	—	unknown	03:00–04:55 (good, 1.92 h)	87.1° 06:05	7.06	100%	75.8°
2038-04-20 Tue	50	—	unknown	03:05–04:50 (good, 1.75 h)	87.1° 06:00	7.0	96%	69.9°
2038-04-21 Wed	52	—	unknown	02:30–04:50 (good, 2.33 h)	87.1° 06:00	6.94	91%	65.4°
2038-04-22 Thu	60	—	unknown	00:35–04:50 (good, 4.25 h)	87.1° 05:55	6.88	83%	62.5°
2038-04-23 Fri	85	—	unknown	23:55–04:45 (good, 4.83 h)	87.1° 05:50	6.82	74%	61.5°
2038-04-24 Sat	92	—	unknown	23:50–04:45 (good, 4.92 h)	87.1° 05:45	6.77	64%	62.3°
2038-04-25 Sun	98	—	unknown	23:50–04:40 (good, 4.83 h)	87.1° 05:40	6.71	53%	64.6°
2038-04-26 Mon	100	—	unknown	23:45–04:40 (good, 4.92 h)	87.1° 05:40	6.65	43%	68.2°
2038-04-27 Tue	100	—	unknown	23:40–04:40 (good, 5.0 h)	87.1° 05:35	6.59	34%	72.6°
2038-04-28 Wed	100	—	unknown	23:35–04:35 (good, 5.0 h)	87.1° 05:30	6.53	25%	77.6°
2038-04-29 Thu	100	—	unknown	23:30–04:35 (good, 5.08 h)	87.1° 05:25	6.47	17%	83.0°
2038-04-30 Fri	100	—	unknown	23:30–04:35 (good, 5.08 h)	87.1° 05:25	6.42	11%	88.6°
2038-05-01 Sat	100	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:20	6.36	6%	94.2°
2038-05-02 Sun	100	—	unknown	23:20–04:30 (good, 5.17 h)	87.1° 05:15	6.3	2%	99.7°
2038-05-03 Mon	100	—	unknown	23:15–04:25 (good, 5.17 h)	87.1° 05:10	6.24	0%	104.8°
2038-05-04 Tue	100	—	unknown	23:15–04:25 (good, 5.17 h)	87.1° 05:05	6.19	0%	109.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-04-05&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.