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: 04-13 (100), 04-14 (100), 04-15 (100), 04-16 (100), 04-17 (100) — by astronomy; check the weather when the night is within four days.

2042-04-03astronomy score per night — click a bar for that night2042-05-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-04-03 Thu	66	—	unknown	02:05–05:25 (good, 3.33 h)	87.1° 07:10	7.97	98%	96.5°
2042-04-04 Fri	62	—	unknown	02:30–05:25 (good, 2.92 h)	87.1° 07:05	7.91	100%	91.9°
2042-04-05 Sat	57	—	unknown	02:45–05:20 (good, 2.58 h)	87.1° 07:00	7.85	100%	87.3°
2042-04-06 Sun	55	—	unknown	02:55–05:20 (good, 2.42 h)	87.1° 06:55	7.8	98%	82.7°
2042-04-07 Mon	54	—	unknown	02:45–05:15 (good, 2.5 h)	87.1° 06:55	7.74	95%	78.4°
2042-04-08 Tue	55	—	unknown	02:15–05:15 (good, 3.0 h)	87.1° 06:50	7.69	90%	74.5°
2042-04-09 Wed	59	—	unknown	01:20–05:15 (good, 3.92 h)	87.1° 06:45	7.63	83%	71.2°
2042-04-10 Thu	73	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:40	7.57	75%	68.7°
2042-04-11 Fri	87	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:35	7.52	66%	67.2°
2042-04-12 Sat	94	—	unknown	00:40–05:10 (good, 4.5 h)	87.1° 06:35	7.46	56%	67.0°
2042-04-13 Sun	100	—	unknown	00:35–05:05 (good, 4.5 h)	87.1° 06:30	7.4	45%	68.0°
2042-04-14 Mon	100	—	unknown	00:30–05:05 (good, 4.58 h)	87.1° 06:25	7.34	34%	70.3°
2042-04-15 Tue	100	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:20	7.29	24%	73.9°
2042-04-16 Wed	100	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:20	7.23	14%	78.5°
2042-04-17 Thu	100	—	unknown	00:20–05:00 (good, 4.67 h)	87.1° 06:15	7.17	7%	84.0°
2042-04-18 Fri	100	—	unknown	00:15–04:55 (good, 4.67 h)	87.1° 06:10	7.11	2%	89.8°
2042-04-19 Sat	100	—	unknown	00:10–04:55 (good, 4.75 h)	87.1° 06:05	7.05	0%	95.7°
2042-04-20 Sun	100	—	unknown	00:10–04:50 (good, 4.67 h)	87.1° 06:00	7.0	1%	101.2°
2042-04-21 Mon	100	—	unknown	00:05–04:50 (good, 4.75 h)	87.1° 06:00	6.94	5%	106.0°
2042-04-22 Tue	100	—	unknown	00:00–04:50 (good, 4.83 h)	87.1° 05:55	6.88	11%	109.6°
2042-04-23 Wed	100	—	unknown	00:00–04:45 (good, 4.75 h)	87.1° 05:50	6.82	19%	112.0°
2042-04-24 Thu	100	—	unknown	23:55–04:45 (good, 4.83 h)	87.1° 05:45	6.76	28%	113.0°
2042-04-25 Fri	100	—	unknown	23:55–04:40 (good, 4.75 h)	87.1° 05:40	6.71	38%	112.8°
2042-04-26 Sat	100	—	unknown	23:55–04:40 (good, 4.75 h)	87.1° 05:40	6.65	48%	111.3°
2042-04-27 Sun	100	—	unknown	23:50–04:40 (good, 4.83 h)	87.1° 05:35	6.59	58%	108.9°
2042-04-28 Mon	100	—	unknown	23:55–04:35 (good, 4.67 h)	87.1° 05:30	6.53	68%	105.7°
2042-04-29 Tue	100	—	unknown	23:55–04:35 (good, 4.67 h)	87.1° 05:25	6.47	76%	101.9°
2042-04-30 Wed	86	—	unknown	23:55–04:35 (good, 4.67 h)	87.1° 05:25	6.41	84%	97.7°
2042-05-01 Thu	82	—	unknown	00:15–04:30 (good, 4.25 h)	87.1° 05:20	6.36	90%	93.2°
2042-05-02 Fri	78	—	unknown	00:40–04:30 (good, 3.83 h)	87.1° 05:15	6.3	95%	88.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-04-03&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.