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: 12-28 (64), 12-27 (63), 12-29 (62), 12-30 (60), 12-31 (57) — by astronomy; check the weather when the night is within four days.

2034-12-22astronomy score per night — click a bar for that night2035-01-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-12-22 Fri	37	—	unknown	18:35–19:45 (good, 1.17 h)	87.3° 15:15	11.51	91%	87.1°
2034-12-23 Sat	40	—	unknown	18:40–20:20 (good, 1.67 h)	87.3° 15:15	11.51	97%	95.4°
2034-12-24 Sun	45	—	unknown	18:40–20:55 (good, 2.25 h)	87.3° 15:10	11.5	100%	103.5°
2034-12-25 Mon	51	—	unknown	18:40–21:05 (good, 2.42 h)	87.3° 15:05	11.5	99%	110.9°
2034-12-26 Tue	56	—	unknown	18:40–21:05 (good, 2.42 h)	87.3° 15:00	11.5	96%	117.0°
2034-12-27 Wed	63	—	unknown	18:40–21:05 (good, 2.42 h)	87.3° 14:55	11.49	91%	121.2°
2034-12-28 Thu	64	—	unknown	18:40–21:05 (good, 2.42 h)	87.3° 14:55	11.48	83%	123.4°
2034-12-29 Fri	62	—	unknown	18:40–21:10 (good, 2.5 h)	87.3° 14:50	11.48	74%	123.3°
2034-12-30 Sat	60	—	unknown	18:40–21:05 (good, 2.42 h)	87.3° 14:45	11.47	65%	121.2°
2034-12-31 Sun	57	—	unknown	18:45–21:00 (good, 2.25 h)	87.3° 14:40	11.46	55%	117.6°
2035-01-01 Mon	55	—	unknown	18:45–20:55 (good, 2.17 h)	87.3° 14:35	11.45	45%	112.8°
2035-01-02 Tue	54	—	unknown	18:45–20:55 (good, 2.17 h)	87.3° 14:35	11.44	36%	107.3°
2035-01-03 Wed	52	—	unknown	18:45–20:50 (good, 2.08 h)	87.3° 14:30	11.43	27%	101.2°
2035-01-04 Thu	50	—	unknown	18:45–20:45 (good, 2.0 h)	87.3° 14:25	11.42	19%	94.8°
2035-01-05 Fri	48	—	unknown	18:45–20:40 (good, 1.92 h)	87.3° 14:20	11.4	12%	88.3°
2035-01-06 Sat	45	—	unknown	18:50–20:35 (good, 1.75 h)	87.3° 14:20	11.39	7%	81.8°
2035-01-07 Sun	44	—	unknown	18:50–20:35 (good, 1.75 h)	87.3° 14:15	11.38	3%	75.5°
2035-01-08 Mon	42	—	unknown	18:50–20:30 (good, 1.67 h)	87.3° 14:10	11.36	1%	69.7°
2035-01-09 Tue	41	—	unknown	18:50–20:25 (good, 1.58 h)	87.3° 14:05	11.34	0%	64.6°
2035-01-10 Wed	38	—	unknown	18:50–20:20 (good, 1.5 h)	87.3° 14:00	11.33	2%	60.4°
2035-01-11 Thu	37	—	unknown	18:50–20:20 (good, 1.5 h)	87.3° 14:00	11.31	5%	57.6°
2035-01-12 Fri	33	—	unknown	18:55–20:15 (good, 1.33 h)	87.3° 13:55	11.29	11%	56.5°
2035-01-13 Sat	29	—	unknown	18:55–20:05 (good, 1.17 h)	87.3° 13:50	11.27	18%	57.3°
2035-01-14 Sun	25	—	unknown	18:55–19:55 (good, 1.0 h)	87.3° 13:45	11.25	26%	59.9°
2035-01-15 Mon	21	—	unknown	18:55–19:45 (good, 0.83 h)	87.3° 13:40	11.23	36%	64.3°
2035-01-16 Tue	18	—	unknown	18:55–19:30 (good, 0.58 h)	87.3° 13:40	11.21	47%	70.0°
2035-01-17 Wed	16	—	unknown	19:00–19:20 (good, 0.33 h)	87.3° 13:35	11.18	58%	76.9°
2035-01-18 Thu	14	—	unknown	18:25–20:25 (marginal, 2.0 h)	87.3° 13:30	11.16	69%	84.4°
2035-01-19 Fri	14	—	unknown	18:25–20:20 (marginal, 1.92 h)	87.3° 13:25	11.14	80%	92.4°
2035-01-20 Sat	14	—	unknown	19:00–19:10 (good, 0.17 h)	87.3° 13:20	11.11	88%	100.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-12-22&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.