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: 01-05 (46), 01-06 (44), 01-07 (43), 01-08 (42), 01-09 (40) — by astronomy; check the weather when the night is within four days.

2045-01-04astronomy score per night — click a bar for that night2045-02-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-01-04 Wed	39	—	unknown	18:45–20:30 (good, 1.75 h)	87.2° 14:25	11.41	96%	114.6°
2045-01-05 Thu	46	—	unknown	18:45–20:30 (good, 1.75 h)	87.3° 14:20	11.4	91%	119.8°
2045-01-06 Fri	44	—	unknown	18:50–20:35 (good, 1.75 h)	87.3° 14:15	11.38	83%	122.8°
2045-01-07 Sat	43	—	unknown	18:50–20:30 (good, 1.67 h)	87.2° 14:10	11.37	73%	123.5°
2045-01-08 Sun	42	—	unknown	18:50–20:30 (good, 1.67 h)	87.2° 14:10	11.35	63%	121.9°
2045-01-09 Mon	40	—	unknown	18:50–20:25 (good, 1.58 h)	87.2° 14:05	11.33	52%	118.5°
2045-01-10 Tue	38	—	unknown	18:50–20:20 (good, 1.5 h)	87.3° 14:00	11.32	42%	113.7°
2045-01-11 Wed	36	—	unknown	18:55–20:15 (good, 1.33 h)	87.3° 13:55	11.3	32%	108.0°
2045-01-12 Thu	34	—	unknown	18:55–20:10 (good, 1.25 h)	87.2° 13:50	11.28	23%	101.7°
2045-01-13 Fri	33	—	unknown	18:55–20:10 (good, 1.25 h)	87.2° 13:50	11.26	16%	95.2°
2045-01-14 Sat	32	—	unknown	18:55–20:05 (good, 1.17 h)	87.3° 13:45	11.24	9%	88.6°
2045-01-15 Sun	30	—	unknown	18:55–20:00 (good, 1.08 h)	87.3° 13:40	11.22	5%	82.0°
2045-01-16 Mon	28	—	unknown	19:00–19:55 (good, 0.92 h)	87.2° 13:35	11.19	2%	75.8°
2045-01-17 Tue	26	—	unknown	19:00–19:50 (good, 0.83 h)	87.2° 13:30	11.17	0%	70.0°
2045-01-18 Wed	26	—	unknown	19:00–19:50 (good, 0.83 h)	87.2° 13:30	11.15	0%	64.9°
2045-01-19 Thu	25	—	unknown	19:00–19:45 (good, 0.75 h)	87.3° 13:25	11.12	3%	60.8°
2045-01-20 Fri	23	—	unknown	19:00–19:40 (good, 0.67 h)	87.3° 13:20	11.1	7%	57.9°
2045-01-21 Sat	19	—	unknown	19:05–19:30 (good, 0.42 h)	87.2° 13:15	11.07	12%	56.5°
2045-01-22 Sun	17	—	unknown	19:05–19:25 (good, 0.33 h)	87.2° 13:15	11.05	19%	56.8°
2045-01-23 Mon	14	—	unknown	19:05–19:15 (good, 0.17 h)	87.2° 13:10	11.02	27%	58.7°
2045-01-24 Tue	12	—	unknown	19:05–20:00 (marginal, 0.92 h)	87.3° 13:05	10.99	37%	62.3°
2045-01-25 Wed	10	—	unknown	19:05–19:55 (marginal, 0.83 h)	87.3° 13:00	10.96	47%	67.3°
2045-01-26 Thu	7	—	unknown	19:10–19:50 (marginal, 0.67 h)	87.2° 12:55	10.93	58%	73.5°
2045-01-27 Fri	7	—	unknown	19:10–19:45 (marginal, 0.58 h)	87.2° 12:55	10.9	68%	80.6°
2045-01-28 Sat	7	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.3° 12:50	10.87	78%	88.3°
2045-01-29 Sun	7	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.3° 12:45	10.84	87%	96.4°
2045-01-30 Mon	7	—	unknown	19:10–19:35 (marginal, 0.42 h)	87.2° 12:40	10.81	94%	104.3°
2045-01-31 Tue	6	—	unknown	05:45–06:00 (marginal, 0.25 h)	87.2° 12:35	10.78	99%	111.6°
2045-02-01 Wed	7	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:35	10.74	100%	117.7°
2045-02-02 Thu	7	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.3° 12:30	10.71	98%	121.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-01-04&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.