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: 03-08 (86), 03-09 (86), 03-10 (86), 03-11 (85), 03-06 (84) — by astronomy; check the weather when the night is within four days.

2041-02-16astronomy score per night — click a bar for that night2041-03-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-02-16 Sat	38	—	unknown	03:45–05:45 (good, 2.0 h)	87.1° 09:10	10.19	99%	102.4°
2041-02-17 Sun	36	—	unknown	03:55–05:40 (good, 1.75 h)	87.1° 09:05	10.15	97%	97.9°
2041-02-18 Mon	35	—	unknown	04:05–05:40 (good, 1.58 h)	87.1° 09:00	10.11	93%	93.1°
2041-02-19 Tue	35	—	unknown	04:05–05:40 (good, 1.58 h)	87.1° 08:55	10.07	87%	88.1°
2041-02-20 Wed	37	—	unknown	03:50–05:40 (good, 1.83 h)	87.1° 08:55	10.03	80%	83.1°
2041-02-21 Thu	38	—	unknown	03:25–05:35 (good, 2.17 h)	87.1° 08:50	9.98	71%	78.4°
2041-02-22 Fri	43	—	unknown	03:15–05:35 (good, 2.33 h)	87.1° 08:45	9.94	61%	74.0°
2041-02-23 Sat	48	—	unknown	03:05–05:35 (good, 2.5 h)	87.1° 08:40	9.9	51%	70.3°
2041-02-24 Sun	55	—	unknown	02:45–05:30 (good, 2.75 h)	87.1° 08:35	9.85	40%	67.5°
2041-02-25 Mon	64	—	unknown	02:40–05:30 (good, 2.83 h)	87.1° 08:35	9.81	29%	66.0°
2041-02-26 Tue	71	—	unknown	02:35–05:30 (good, 2.92 h)	87.1° 08:30	9.77	20%	66.0°
2041-02-27 Wed	74	—	unknown	02:30–05:25 (good, 2.92 h)	87.1° 08:25	9.72	11%	67.7°
2041-02-28 Thu	77	—	unknown	02:25–05:25 (good, 3.0 h)	87.1° 08:20	9.68	5%	70.9°
2041-03-01 Fri	78	—	unknown	02:25–05:25 (good, 3.0 h)	87.1° 08:20	9.63	1%	75.4°
2041-03-02 Sat	79	—	unknown	02:20–05:25 (good, 3.08 h)	87.1° 08:15	9.58	0%	80.9°
2041-03-03 Sun	80	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 08:10	9.54	3%	86.8°
2041-03-04 Mon	81	—	unknown	02:10–05:20 (good, 3.17 h)	87.1° 08:05	9.49	8%	92.8°
2041-03-05 Tue	83	—	unknown	02:10–05:20 (good, 3.17 h)	87.1° 08:00	9.45	15%	98.5°
2041-03-06 Wed	84	—	unknown	02:05–05:15 (good, 3.17 h)	87.1° 08:00	9.4	23%	103.5°
2041-03-07 Thu	84	—	unknown	02:00–05:15 (good, 3.25 h)	87.1° 07:55	9.35	33%	107.7°
2041-03-08 Fri	86	—	unknown	01:55–05:15 (good, 3.33 h)	87.1° 07:50	9.3	43%	110.9°
2041-03-09 Sat	86	—	unknown	02:00–05:10 (good, 3.17 h)	87.1° 07:45	9.25	53%	113.0°
2041-03-10 Sun	86	—	unknown	01:55–05:10 (good, 3.25 h)	87.1° 07:40	9.21	62%	114.0°
2041-03-11 Mon	85	—	unknown	01:55–05:10 (good, 3.25 h)	87.1° 07:40	9.16	71%	113.9°
2041-03-12 Tue	82	—	unknown	01:55–05:05 (good, 3.17 h)	87.1° 07:35	9.11	80%	112.6°
2041-03-13 Wed	71	—	unknown	01:55–05:05 (good, 3.17 h)	87.1° 07:30	9.06	86%	110.4°
2041-03-14 Thu	66	—	unknown	01:55–05:00 (good, 3.08 h)	87.1° 07:25	9.01	92%	107.3°
2041-03-15 Fri	62	—	unknown	01:55–05:00 (good, 3.08 h)	87.1° 07:25	8.96	96%	103.5°
2041-03-16 Sat	57	—	unknown	02:10–05:00 (good, 2.83 h)	87.1° 07:20	8.91	99%	99.2°
2041-03-17 Sun	52	—	unknown	02:30–04:55 (good, 2.42 h)	87.1° 07:15	8.86	100%	94.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-02-16&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.