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: 03-06 (83), 03-07 (83), 03-04 (82), 03-05 (82), 03-03 (80) — by astronomy; check the weather when the night is within four days.

2044-02-18astronomy score per night — click a bar for that night2044-03-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-02-18 Thu	39	—	unknown	03:35–05:40 (good, 2.08 h)	87.1° 09:05	10.14	68%	82.6°
2044-02-19 Fri	43	—	unknown	03:25–05:40 (good, 2.25 h)	87.1° 09:00	10.1	59%	78.2°
2044-02-20 Sat	47	—	unknown	03:15–05:40 (good, 2.42 h)	87.1° 08:55	10.06	49%	74.2°
2044-02-21 Sun	53	—	unknown	03:00–05:35 (good, 2.58 h)	87.1° 08:50	10.01	40%	70.9°
2044-02-22 Mon	59	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:50	9.97	31%	68.5°
2044-02-23 Tue	64	—	unknown	02:50–05:35 (good, 2.75 h)	87.1° 08:45	9.93	22%	66.9°
2044-02-24 Wed	71	—	unknown	02:45–05:35 (good, 2.83 h)	87.1° 08:40	9.89	15%	66.4°
2044-02-25 Thu	72	—	unknown	02:40–05:30 (good, 2.83 h)	87.1° 08:35	9.84	9%	67.0°
2044-02-26 Fri	73	—	unknown	02:40–05:30 (good, 2.83 h)	87.1° 08:30	9.8	4%	68.7°
2044-02-27 Sat	75	—	unknown	02:35–05:30 (good, 2.92 h)	87.1° 08:30	9.75	1%	71.5°
2044-02-28 Sun	75	—	unknown	02:30–05:25 (good, 2.92 h)	87.1° 08:25	9.71	0%	75.3°
2044-02-29 Mon	77	—	unknown	02:25–05:25 (good, 3.0 h)	87.1° 08:20	9.66	1%	79.9°
2044-03-01 Tue	78	—	unknown	02:20–05:25 (good, 3.08 h)	87.1° 08:15	9.62	5%	85.1°
2044-03-02 Wed	79	—	unknown	02:20–05:20 (good, 3.0 h)	87.1° 08:15	9.57	11%	90.5°
2044-03-03 Thu	80	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 08:10	9.53	19%	96.0°
2044-03-04 Fri	82	—	unknown	02:10–05:20 (good, 3.17 h)	87.1° 08:05	9.48	28%	101.2°
2044-03-05 Sat	82	—	unknown	02:05–05:15 (good, 3.17 h)	87.1° 08:00	9.43	39%	105.9°
2044-03-06 Sun	83	—	unknown	02:10–05:15 (good, 3.08 h)	87.1° 07:55	9.38	51%	109.7°
2044-03-07 Mon	83	—	unknown	02:05–05:15 (good, 3.17 h)	87.1° 07:55	9.34	62%	112.3°
2044-03-08 Tue	80	—	unknown	02:05–05:10 (good, 3.08 h)	87.1° 07:50	9.29	73%	113.5°
2044-03-09 Wed	79	—	unknown	02:05–05:10 (good, 3.08 h)	87.1° 07:45	9.24	82%	113.2°
2044-03-10 Thu	69	—	unknown	02:05–05:10 (good, 3.08 h)	87.1° 07:40	9.19	90%	111.5°
2044-03-11 Fri	64	—	unknown	02:05–05:05 (good, 3.0 h)	87.1° 07:35	9.14	96%	108.4°
2044-03-12 Sat	61	—	unknown	02:05–05:05 (good, 3.0 h)	87.1° 07:35	9.09	99%	104.4°
2044-03-13 Sun	56	—	unknown	02:15–05:05 (good, 2.83 h)	87.1° 07:30	9.04	100%	99.7°
2044-03-14 Mon	52	—	unknown	02:25–05:00 (good, 2.58 h)	87.1° 07:25	8.99	99%	94.6°
2044-03-15 Tue	51	—	unknown	02:30–05:00 (good, 2.5 h)	87.1° 07:20	8.94	95%	89.5°
2044-03-16 Wed	51	—	unknown	02:20–05:00 (good, 2.67 h)	87.1° 07:20	8.89	90%	84.5°
2044-03-17 Thu	52	—	unknown	01:55–04:55 (good, 3.0 h)	87.1° 07:15	8.84	83%	79.8°
2044-03-18 Fri	55	—	unknown	01:40–04:55 (good, 3.25 h)	87.1° 07:10	8.79	75%	75.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-02-18&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.