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: 03-16 (93), 03-17 (93), 03-14 (92), 03-15 (92), 03-18 (92) — by astronomy; check the weather when the night is within four days.

2035-02-17astronomy score per night — click a bar for that night2035-03-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-02-17 Sat	61	—	unknown	03:20–05:40 (good, 2.33 h)	87.1° 09:05	10.17	76%	122.3°
2035-02-18 Sun	61	—	unknown	03:15–05:40 (good, 2.42 h)	87.1° 09:05	10.13	85%	122.8°
2035-02-19 Mon	60	—	unknown	03:15–05:40 (good, 2.42 h)	87.1° 09:00	10.09	92%	121.0°
2035-02-20 Tue	53	—	unknown	03:15–05:40 (good, 2.42 h)	87.1° 08:55	10.05	97%	117.3°
2035-02-21 Wed	49	—	unknown	03:15–05:35 (good, 2.33 h)	87.1° 08:50	10.01	100%	111.9°
2035-02-22 Thu	45	—	unknown	03:20–05:35 (good, 2.25 h)	87.1° 08:45	9.96	100%	105.6°
2035-02-23 Fri	42	—	unknown	03:30–05:35 (good, 2.08 h)	87.1° 08:45	9.92	97%	98.7°
2035-02-24 Sat	39	—	unknown	03:45–05:35 (good, 1.83 h)	87.1° 08:40	9.88	92%	91.7°
2035-02-25 Sun	37	—	unknown	03:55–05:30 (good, 1.58 h)	87.1° 08:35	9.83	86%	84.8°
2035-02-26 Mon	38	—	unknown	03:50–05:30 (good, 1.67 h)	87.1° 08:30	9.79	79%	78.2°
2035-02-27 Tue	40	—	unknown	03:20–05:30 (good, 2.17 h)	87.1° 08:25	9.75	70%	72.2°
2035-02-28 Wed	43	—	unknown	02:55–05:25 (good, 2.5 h)	87.1° 08:25	9.7	61%	66.9°
2035-03-01 Thu	48	—	unknown	02:45–05:25 (good, 2.67 h)	87.1° 08:20	9.66	52%	62.5°
2035-03-02 Fri	55	—	unknown	02:35–05:25 (good, 2.83 h)	87.1° 08:15	9.61	42%	59.3°
2035-03-03 Sat	63	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 08:10	9.56	33%	57.5°
2035-03-04 Sun	71	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 08:10	9.52	24%	57.2°
2035-03-05 Mon	77	—	unknown	02:10–05:20 (good, 3.17 h)	87.1° 08:05	9.47	17%	58.5°
2035-03-06 Tue	82	—	unknown	02:05–05:15 (good, 3.17 h)	87.1° 08:00	9.42	10%	61.5°
2035-03-07 Wed	84	—	unknown	02:00–05:15 (good, 3.25 h)	87.1° 07:55	9.38	5%	65.9°
2035-03-08 Thu	86	—	unknown	02:00–05:15 (good, 3.25 h)	87.1° 07:50	9.33	1%	71.6°
2035-03-09 Fri	86	—	unknown	01:55–05:10 (good, 3.25 h)	87.1° 07:50	9.28	0%	78.2°
2035-03-10 Sat	88	—	unknown	01:50–05:10 (good, 3.33 h)	87.1° 07:45	9.23	1%	85.4°
2035-03-11 Sun	89	—	unknown	01:45–05:10 (good, 3.42 h)	87.1° 07:40	9.18	5%	93.0°
2035-03-12 Mon	89	—	unknown	01:40–05:05 (good, 3.42 h)	87.1° 07:35	9.13	11%	100.5°
2035-03-13 Tue	91	—	unknown	01:40–05:05 (good, 3.42 h)	87.1° 07:30	9.09	19%	107.5°
2035-03-14 Wed	92	—	unknown	01:35–05:05 (good, 3.5 h)	87.1° 07:30	9.04	29%	113.8°
2035-03-15 Thu	92	—	unknown	01:30–05:00 (good, 3.5 h)	87.1° 07:25	8.99	40%	118.7°
2035-03-16 Fri	93	—	unknown	01:30–05:00 (good, 3.5 h)	87.1° 07:20	8.94	51%	121.9°
2035-03-17 Sat	93	—	unknown	01:30–05:00 (good, 3.5 h)	87.1° 07:15	8.88	62%	122.9°
2035-03-18 Sun	92	—	unknown	01:25–04:55 (good, 3.5 h)	87.1° 07:15	8.83	73%	121.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-02-17&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.