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: 11-30 (92), 12-15 (88), 12-16 (88), 12-01 (87), 12-17 (87) — by astronomy; check the weather when the night is within four days.

2038-11-30astronomy score per night — click a bar for that night2038-12-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-11-30 Tue	92	—	unknown	18:35–23:05 (good, 4.5 h)	87.3° 16:45	11.31	24%	65.8°
2038-12-01 Wed	87	—	unknown	18:35–23:00 (good, 4.42 h)	87.3° 16:40	11.33	34%	63.2°
2038-12-02 Thu	77	—	unknown	18:35–22:40 (good, 4.08 h)	87.3° 16:35	11.35	44%	62.3°
2038-12-03 Fri	66	—	unknown	18:35–22:25 (good, 3.83 h)	87.3° 16:30	11.37	54%	62.8°
2038-12-04 Sat	56	—	unknown	18:35–22:00 (good, 3.42 h)	87.2° 16:25	11.38	64%	64.6°
2038-12-05 Sun	50	—	unknown	18:35–20:40 (good, 2.08 h)	87.3° 16:25	11.39	72%	67.6°
2038-12-06 Mon	46	—	unknown	18:35–20:00 (good, 1.42 h)	87.3° 16:20	11.41	80%	71.4°
2038-12-07 Tue	44	—	unknown	18:35–19:50 (good, 1.25 h)	87.3° 16:15	11.42	87%	76.0°
2038-12-08 Wed	45	—	unknown	18:35–19:55 (good, 1.33 h)	87.3° 16:10	11.43	93%	81.0°
2038-12-09 Thu	48	—	unknown	18:35–20:15 (good, 1.67 h)	87.2° 16:10	11.44	97%	86.4°
2038-12-10 Fri	53	—	unknown	18:35–20:45 (good, 2.17 h)	87.3° 16:05	11.45	99%	92.0°
2038-12-11 Sat	59	—	unknown	18:35–21:20 (good, 2.75 h)	87.3° 16:00	11.46	100%	97.5°
2038-12-12 Sun	65	—	unknown	18:35–21:45 (good, 3.17 h)	87.3° 15:55	11.47	99%	102.8°
2038-12-13 Mon	71	—	unknown	18:35–21:50 (good, 3.25 h)	87.3° 15:50	11.48	96%	107.7°
2038-12-14 Tue	86	—	unknown	18:35–21:50 (good, 3.25 h)	87.3° 15:50	11.49	90%	111.9°
2038-12-15 Wed	88	—	unknown	18:35–21:50 (good, 3.25 h)	87.3° 15:45	11.49	84%	115.2°
2038-12-16 Thu	88	—	unknown	18:35–21:50 (good, 3.25 h)	87.3° 15:40	11.5	75%	117.2°
2038-12-17 Fri	87	—	unknown	18:35–21:55 (good, 3.33 h)	87.3° 15:35	11.5	66%	117.7°
2038-12-18 Sat	85	—	unknown	18:35–21:50 (good, 3.25 h)	87.3° 15:30	11.5	55%	116.6°
2038-12-19 Sun	84	—	unknown	18:35–21:50 (good, 3.25 h)	87.3° 15:30	11.51	44%	114.0°
2038-12-20 Mon	81	—	unknown	18:35–21:45 (good, 3.17 h)	87.3° 15:25	11.51	33%	109.8°
2038-12-21 Tue	78	—	unknown	18:35–21:40 (good, 3.08 h)	87.3° 15:20	11.51	23%	104.4°
2038-12-22 Wed	76	—	unknown	18:35–21:35 (good, 3.0 h)	87.3° 15:15	11.51	14%	98.1°
2038-12-23 Thu	73	—	unknown	18:40–21:30 (good, 2.83 h)	87.2° 15:15	11.51	6%	91.3°
2038-12-24 Fri	72	—	unknown	18:40–21:30 (good, 2.83 h)	87.3° 15:10	11.5	2%	84.4°
2038-12-25 Sat	70	—	unknown	18:40–21:25 (good, 2.75 h)	87.3° 15:05	11.5	0%	77.8°
2038-12-26 Sun	68	—	unknown	18:40–21:20 (good, 2.67 h)	87.3° 15:00	11.5	1%	72.0°
2038-12-27 Mon	66	—	unknown	18:40–21:15 (good, 2.58 h)	87.3° 14:55	11.49	5%	67.3°
2038-12-28 Tue	61	—	unknown	18:40–21:15 (good, 2.58 h)	87.3° 14:55	11.48	11%	64.1°
2038-12-29 Wed	55	—	unknown	18:40–21:10 (good, 2.5 h)	87.3° 14:50	11.48	18%	62.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-11-30&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.