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: 12-12 (97), 12-13 (95), 12-14 (94), 12-15 (88), 12-16 (80) — by astronomy; check the weather when the night is within four days.

2042-12-12astronomy score per night — click a bar for that night2043-01-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2043-01-02 Fri	54	—	unknown	18:45–20:55 (good, 2.17 h)	87.2° 14:35	11.44	53%	117.6°
2043-01-03 Sat	52	—	unknown	18:45–20:50 (good, 2.08 h)	87.3° 14:30	11.43	44%	114.4°
2043-01-04 Sun	50	—	unknown	18:45–20:45 (good, 2.0 h)	87.3° 14:25	11.42	34%	110.3°
2043-01-05 Mon	48	—	unknown	18:45–20:40 (good, 1.92 h)	87.3° 14:20	11.4	26%	105.4°
2043-01-06 Tue	46	—	unknown	18:50–20:40 (good, 1.83 h)	87.2° 14:20	11.39	18%	99.9°
2043-01-07 Wed	44	—	unknown	18:50–20:35 (good, 1.75 h)	87.3° 14:15	11.38	11%	94.0°
2043-01-08 Thu	42	—	unknown	18:50–20:30 (good, 1.67 h)	87.3° 14:10	11.36	6%	87.8°
2043-01-09 Fri	41	—	unknown	18:50–20:25 (good, 1.58 h)	87.3° 14:05	11.34	2%	81.6°
2043-01-10 Sat	38	—	unknown	18:50–20:20 (good, 1.5 h)	87.2° 14:00	11.33	0%	75.6°

Download: CSV · JSON

💡 API

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