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 Vega: 11-27 (48), 11-28 (48), 11-29 (46), 11-30 (44), 12-01 (43) — by astronomy; check the weather when the night is within four days.

2026-11-25astronomy score per night — click a bar for that night2026-12-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2026-11-25 Wed	39	—	unknown	18:35–20:25 (good, 1.83 h)	87.1° 14:40	11.21	97%	111.4°
2026-11-26 Thu	42	—	unknown	18:35–20:25 (good, 1.83 h)	87.1° 14:35	11.23	92%	114.3°
2026-11-27 Fri	48	—	unknown	18:35–20:25 (good, 1.83 h)	87.1° 14:35	11.26	84%	115.4°
2026-11-28 Sat	48	—	unknown	18:35–20:30 (good, 1.92 h)	87.1° 14:30	11.28	75%	114.7°
2026-11-29 Sun	46	—	unknown	18:35–20:25 (good, 1.83 h)	87.1° 14:25	11.3	65%	112.4°
2026-11-30 Mon	44	—	unknown	18:35–20:20 (good, 1.75 h)	87.1° 14:20	11.31	54%	108.9°
2026-12-01 Tue	43	—	unknown	18:35–20:15 (good, 1.67 h)	87.1° 14:15	11.33	43%	104.4°
2026-12-02 Wed	42	—	unknown	18:35–20:15 (good, 1.67 h)	87.1° 14:15	11.35	33%	99.4°
2026-12-03 Thu	40	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:10	11.36	23%	94.0°
2026-12-04 Fri	38	—	unknown	18:35–20:05 (good, 1.5 h)	87.1° 14:05	11.38	16%	88.6°
2026-12-05 Sat	37	—	unknown	18:35–20:00 (good, 1.42 h)	87.1° 14:00	11.39	9%	83.4°
2026-12-06 Sun	36	—	unknown	18:35–19:55 (good, 1.33 h)	87.1° 14:00	11.41	4%	78.4°
2026-12-07 Mon	34	—	unknown	18:35–19:55 (good, 1.33 h)	87.1° 13:55	11.42	1%	74.0°
2026-12-08 Tue	33	—	unknown	18:35–19:50 (good, 1.25 h)	87.1° 13:50	11.43	0%	70.2°
2026-12-09 Wed	31	—	unknown	18:35–19:45 (good, 1.17 h)	87.1° 13:45	11.44	1%	67.3°
2026-12-10 Thu	30	—	unknown	18:35–19:40 (good, 1.08 h)	87.1° 13:40	11.45	3%	65.4°
2026-12-11 Fri	29	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 13:40	11.46	7%	64.5°
2026-12-12 Sat	26	—	unknown	18:35–19:30 (good, 0.92 h)	87.1° 13:35	11.47	13%	64.8°
2026-12-13 Sun	23	—	unknown	18:35–19:25 (good, 0.83 h)	87.1° 13:30	11.48	20%	66.3°
2026-12-14 Mon	20	—	unknown	18:35–19:15 (good, 0.67 h)	87.1° 13:25	11.49	28%	68.8°
2026-12-15 Tue	18	—	unknown	18:35–19:05 (good, 0.5 h)	87.1° 13:20	11.49	37%	72.3°
2026-12-16 Wed	15	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 13:20	11.5	47%	76.7°
2026-12-17 Thu	13	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:15	11.5	57%	81.7°
2026-12-18 Fri	12	—	unknown	18:35–18:40 (good, 0.08 h)	87.1° 13:10	11.5	67%	87.2°
2026-12-19 Sat	12	—	unknown	18:00–19:35 (marginal, 1.58 h)	87.1° 13:05	11.51	77%	93.1°
2026-12-20 Sun	11	—	unknown	18:00–19:35 (marginal, 1.58 h)	87.1° 13:05	11.51	86%	99.0°
2026-12-21 Mon	10	—	unknown	18:05–19:30 (marginal, 1.42 h)	87.1° 13:00	11.51	93%	104.7°
2026-12-22 Tue	10	—	unknown	18:05–19:25 (marginal, 1.33 h)	87.1° 12:55	11.51	98%	109.6°
2026-12-23 Wed	9	—	unknown	18:40–19:20 (marginal, 0.67 h)	87.1° 12:50	11.51	100%	113.2°
2026-12-24 Thu	10	—	unknown	18:40–19:20 (marginal, 0.67 h)	87.1° 12:45	11.5	99%	115.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-11-25&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.