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: 11-30 (43), 12-01 (43), 11-29 (42), 12-02 (42), 12-03 (40) — by astronomy; check the weather when the night is within four days.

2042-11-27astronomy score per night — click a bar for that night2042-12-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-11-27 Thu	35	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:35	11.26	99%	109.9°
2042-11-28 Fri	37	—	unknown	18:35–20:15 (good, 1.67 h)	87.1° 14:30	11.28	96%	112.3°
2042-11-29 Sat	42	—	unknown	18:35–20:15 (good, 1.67 h)	87.1° 14:25	11.3	90%	113.2°
2042-11-30 Sun	43	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:20	11.32	83%	112.6°
2042-12-01 Mon	43	—	unknown	18:35–20:15 (good, 1.67 h)	87.1° 14:15	11.33	74%	110.7°
2042-12-02 Tue	42	—	unknown	18:35–20:15 (good, 1.67 h)	87.1° 14:15	11.35	64%	107.8°
2042-12-03 Wed	40	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:10	11.37	55%	104.2°
2042-12-04 Thu	38	—	unknown	18:35–20:05 (good, 1.5 h)	87.1° 14:05	11.38	45%	100.1°
2042-12-05 Fri	37	—	unknown	18:35–20:00 (good, 1.42 h)	87.1° 14:00	11.4	36%	95.6°
2042-12-06 Sat	36	—	unknown	18:35–19:55 (good, 1.33 h)	87.1° 14:00	11.41	27%	91.0°
2042-12-07 Sun	34	—	unknown	18:35–19:55 (good, 1.33 h)	87.1° 13:55	11.42	19%	86.3°
2042-12-08 Mon	33	—	unknown	18:35–19:50 (good, 1.25 h)	87.1° 13:50	11.43	12%	81.8°
2042-12-09 Tue	31	—	unknown	18:35–19:45 (good, 1.17 h)	87.1° 13:45	11.44	7%	77.6°
2042-12-10 Wed	30	—	unknown	18:35–19:40 (good, 1.08 h)	87.1° 13:40	11.45	3%	73.8°
2042-12-11 Thu	29	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 13:40	11.46	1%	70.6°
2042-12-12 Fri	28	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 13:35	11.47	0%	68.3°
2042-12-13 Sat	26	—	unknown	18:35–19:30 (good, 0.92 h)	87.1° 13:30	11.48	2%	67.0°
2042-12-14 Sun	25	—	unknown	18:35–19:25 (good, 0.83 h)	87.1° 13:25	11.49	6%	66.8°
2042-12-15 Mon	23	—	unknown	18:35–19:20 (good, 0.75 h)	87.1° 13:20	11.49	11%	67.9°
2042-12-16 Tue	20	—	unknown	18:35–19:10 (good, 0.58 h)	87.1° 13:20	11.5	19%	70.2°
2042-12-17 Wed	18	—	unknown	18:35–19:05 (good, 0.5 h)	87.1° 13:15	11.5	28%	73.6°
2042-12-18 Thu	15	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 13:10	11.5	38%	77.8°
2042-12-19 Fri	14	—	unknown	18:35–18:45 (good, 0.17 h)	87.1° 13:05	11.51	49%	82.8°
2042-12-20 Sat	12	—	unknown	18:35–18:40 (good, 0.08 h)	87.1° 13:05	11.51	60%	88.2°
2042-12-21 Sun	10	—	unknown	18:35–19:30 (marginal, 0.92 h)	87.1° 13:00	11.51	71%	93.8°
2042-12-22 Mon	9	—	unknown	18:35–19:25 (marginal, 0.83 h)	87.1° 12:55	11.51	81%	99.3°
2042-12-23 Tue	8	—	unknown	18:40–19:20 (marginal, 0.67 h)	87.1° 12:50	11.51	89%	104.3°
2042-12-24 Wed	8	—	unknown	18:40–19:20 (marginal, 0.67 h)	87.1° 12:45	11.5	95%	108.5°
2042-12-25 Thu	8	—	unknown	18:40–19:15 (marginal, 0.58 h)	87.1° 12:45	11.5	99%	111.5°
2042-12-26 Fri	8	—	unknown	18:40–19:10 (marginal, 0.5 h)	87.1° 12:40	11.5	100%	113.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-11-27&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.