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 V1057 Cyg: 12-03 (100), 12-04 (100), 12-05 (100), 12-06 (100), 12-07 (100) — by astronomy; check the weather when the night is within four days.

2042-12-03astronomy score per night — click a bar for that night2043-01-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-12-03 Wed	100	—	unknown	18:35–22:50 (good, 4.25 h)	87.3° 16:30	11.37	55%	119.3°
2042-12-04 Thu	100	—	unknown	18:35–22:45 (good, 4.17 h)	87.2° 16:25	11.38	45%	119.7°
2042-12-05 Fri	100	—	unknown	18:35–22:45 (good, 4.17 h)	87.3° 16:25	11.4	36%	118.8°
2042-12-06 Sat	100	—	unknown	18:35–22:40 (good, 4.08 h)	87.3° 16:20	11.41	27%	116.5°
2042-12-07 Sun	100	—	unknown	18:35–22:35 (good, 4.0 h)	87.3° 16:15	11.42	19%	113.0°
2042-12-08 Mon	100	—	unknown	18:35–22:30 (good, 3.92 h)	87.3° 16:10	11.43	12%	108.7°
2042-12-09 Tue	100	—	unknown	18:35–22:30 (good, 3.92 h)	87.2° 16:10	11.44	7%	103.6°
2042-12-10 Wed	100	—	unknown	18:35–22:25 (good, 3.83 h)	87.3° 16:05	11.45	3%	98.0°
2042-12-11 Thu	99	—	unknown	18:35–22:20 (good, 3.75 h)	87.3° 16:00	11.46	1%	92.0°
2042-12-12 Fri	97	—	unknown	18:35–22:15 (good, 3.67 h)	87.3° 15:55	11.47	0%	85.8°
2042-12-13 Sat	95	—	unknown	18:35–22:10 (good, 3.58 h)	87.2° 15:50	11.48	2%	79.8°
2042-12-14 Sun	94	—	unknown	18:35–22:10 (good, 3.58 h)	87.2° 15:50	11.49	6%	74.0°
2042-12-15 Mon	88	—	unknown	18:35–22:05 (good, 3.5 h)	87.3° 15:45	11.49	11%	68.8°
2042-12-16 Tue	80	—	unknown	18:35–22:00 (good, 3.42 h)	87.3° 15:40	11.5	19%	64.5°
2042-12-17 Wed	70	—	unknown	18:35–21:55 (good, 3.33 h)	87.3° 15:35	11.5	28%	61.5°
2042-12-18 Thu	59	—	unknown	18:35–21:35 (good, 3.0 h)	87.2° 15:30	11.5	38%	60.2°
2042-12-19 Fri	49	—	unknown	18:35–21:20 (good, 2.75 h)	87.2° 15:30	11.51	49%	60.6°
2042-12-20 Sat	40	—	unknown	18:35–20:25 (good, 1.83 h)	87.3° 15:25	11.51	60%	63.0°
2042-12-21 Sun	34	—	unknown	18:35–19:15 (good, 0.67 h)	87.3° 15:20	11.51	71%	67.1°
2042-12-22 Mon	30	—	unknown	18:35–18:50 (good, 0.25 h)	87.3° 15:15	11.51	81%	72.6°
2042-12-23 Tue	30	—	unknown	18:40–18:55 (good, 0.25 h)	87.2° 15:15	11.51	89%	79.1°
2042-12-24 Wed	32	—	unknown	18:40–19:20 (good, 0.67 h)	87.3° 15:10	11.5	95%	86.2°
2042-12-25 Thu	36	—	unknown	18:40–20:00 (good, 1.33 h)	87.3° 15:05	11.5	99%	93.5°
2042-12-26 Fri	42	—	unknown	18:40–20:45 (good, 2.08 h)	87.3° 15:00	11.5	100%	100.5°
2042-12-27 Sat	47	—	unknown	18:40–20:55 (good, 2.25 h)	87.2° 14:55	11.49	98%	106.9°
2042-12-28 Sun	58	—	unknown	18:40–20:55 (good, 2.25 h)	87.2° 14:55	11.48	94%	112.2°
2042-12-29 Mon	59	—	unknown	18:40–21:00 (good, 2.33 h)	87.3° 14:50	11.48	88%	116.3°
2042-12-30 Tue	59	—	unknown	18:40–21:05 (good, 2.42 h)	87.3° 14:45	11.47	80%	119.0°
2042-12-31 Wed	57	—	unknown	18:45–21:00 (good, 2.25 h)	87.3° 14:40	11.46	72%	120.0°
2043-01-01 Thu	55	—	unknown	18:45–20:55 (good, 2.17 h)	87.2° 14:35	11.45	62%	119.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-12-03&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.