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: 10-26 (94), 10-27 (94), 10-28 (93), 10-24 (92), 10-25 (92) — by astronomy; check the weather when the night is within four days.

2040-10-17astronomy score per night — click a bar for that night2040-11-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2040-10-17 Wed	54	—	unknown	20:10–22:35 (good, 2.42 h)	87.1° 18:10	9.93	93%	84.8°
2040-10-18 Thu	56	—	unknown	20:10–22:45 (good, 2.58 h)	87.1° 18:10	9.98	98%	90.6°
2040-10-19 Fri	60	—	unknown	20:10–23:00 (good, 2.83 h)	87.1° 18:05	10.02	100%	96.3°
2040-10-20 Sat	66	—	unknown	20:05–23:30 (good, 3.42 h)	87.1° 18:00	10.06	99%	101.6°
2040-10-21 Sun	71	—	unknown	20:05–23:30 (good, 3.42 h)	87.1° 17:55	10.1	97%	106.2°
2040-10-22 Mon	77	—	unknown	20:05–23:35 (good, 3.5 h)	87.1° 17:55	10.14	92%	109.9°
2040-10-23 Tue	89	—	unknown	20:05–23:35 (good, 3.5 h)	87.1° 17:50	10.18	86%	112.5°
2040-10-24 Wed	92	—	unknown	20:00–23:35 (good, 3.58 h)	87.1° 17:45	10.22	78%	114.1°
2040-10-25 Thu	92	—	unknown	20:00–23:30 (good, 3.5 h)	87.1° 17:40	10.26	69%	114.4°
2040-10-26 Fri	94	—	unknown	20:00–23:30 (good, 3.5 h)	87.1° 17:35	10.3	60%	113.6°
2040-10-27 Sat	94	—	unknown	19:55–23:30 (good, 3.58 h)	87.1° 17:35	10.34	51%	111.8°
2040-10-28 Sun	93	—	unknown	18:55–22:30 (good, 3.58 h)	87.1° 16:30	10.38	42%	109.1°
2040-10-29 Mon	91	—	unknown	18:55–22:25 (good, 3.5 h)	87.1° 16:25	10.41	32%	105.5°
2040-10-30 Tue	90	—	unknown	18:55–22:20 (good, 3.42 h)	87.1° 16:20	10.45	24%	101.2°
2040-10-31 Wed	89	—	unknown	18:55–22:15 (good, 3.33 h)	87.1° 16:15	10.49	16%	96.4°
2040-11-01 Thu	89	—	unknown	18:50–22:15 (good, 3.42 h)	87.1° 16:15	10.52	9%	91.3°
2040-11-02 Fri	86	—	unknown	18:50–22:10 (good, 3.33 h)	87.1° 16:10	10.56	4%	86.0°
2040-11-03 Sat	85	—	unknown	18:50–22:05 (good, 3.25 h)	87.1° 16:05	10.59	1%	80.7°
2040-11-04 Sun	84	—	unknown	18:50–22:00 (good, 3.17 h)	87.1° 16:00	10.63	0%	75.7°
2040-11-05 Mon	83	—	unknown	18:45–21:55 (good, 3.17 h)	87.1° 16:00	10.66	2%	71.4°
2040-11-06 Tue	81	—	unknown	18:45–21:55 (good, 3.17 h)	87.1° 15:55	10.7	6%	68.1°
2040-11-07 Wed	77	—	unknown	18:45–21:50 (good, 3.08 h)	87.1° 15:50	10.73	12%	66.1°
2040-11-08 Thu	70	—	unknown	18:45–21:45 (good, 3.0 h)	87.1° 15:45	10.76	21%	65.6°
2040-11-09 Fri	63	—	unknown	18:45–21:40 (good, 2.92 h)	87.1° 15:40	10.8	31%	66.8°
2040-11-10 Sat	55	—	unknown	18:45–21:25 (good, 2.67 h)	87.1° 15:40	10.83	42%	69.4°
2040-11-11 Sun	49	—	unknown	18:40–21:15 (good, 2.58 h)	87.1° 15:35	10.86	53%	73.3°
2040-11-12 Mon	43	—	unknown	18:40–21:05 (good, 2.42 h)	87.1° 15:30	10.89	64%	78.0°
2040-11-13 Tue	39	—	unknown	18:40–20:50 (good, 2.17 h)	87.1° 15:25	10.92	75%	83.3°
2040-11-14 Wed	38	—	unknown	18:40–20:30 (good, 1.83 h)	87.1° 15:20	10.95	84%	88.9°
2040-11-15 Thu	38	—	unknown	18:40–20:30 (good, 1.83 h)	87.1° 15:20	10.98	91%	94.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2040-10-17&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.