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: 02-21 (67), 02-20 (64), 02-19 (58), 02-18 (53), 02-03 (47) — by astronomy; check the weather when the night is within four days.

2047-01-23astronomy score per night — click a bar for that night2047-02-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-01-23 Wed	33	—	unknown	04:50–06:05 (good, 1.25 h)	87.1° 10:45	11.03	5%	63.6°
2047-01-24 Thu	34	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:40	11.0	1%	62.3°
2047-01-25 Fri	36	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:35	10.98	0%	62.6°
2047-01-26 Sat	37	—	unknown	04:40–06:05 (good, 1.42 h)	87.1° 10:35	10.95	1%	64.4°
2047-01-27 Sun	38	—	unknown	04:35–06:05 (good, 1.5 h)	87.1° 10:30	10.92	4%	67.4°
2047-01-28 Mon	39	—	unknown	04:30–06:05 (good, 1.58 h)	87.1° 10:25	10.89	8%	71.4°
2047-01-29 Tue	40	—	unknown	04:25–06:00 (good, 1.58 h)	87.1° 10:20	10.86	14%	76.2°
2047-01-30 Wed	41	—	unknown	04:25–06:00 (good, 1.58 h)	87.1° 10:20	10.82	22%	81.3°
2047-01-31 Thu	42	—	unknown	04:20–06:00 (good, 1.67 h)	87.1° 10:15	10.79	30%	86.7°
2047-02-01 Fri	43	—	unknown	04:15–06:00 (good, 1.75 h)	87.1° 10:10	10.76	39%	92.2°
2047-02-02 Sat	45	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:05	10.73	48%	97.7°
2047-02-03 Sun	47	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:00	10.69	58%	102.9°
2047-02-04 Mon	47	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 10:00	10.66	67%	107.8°
2047-02-05 Tue	47	—	unknown	04:10–05:55 (good, 1.75 h)	87.1° 09:55	10.62	76%	112.0°
2047-02-06 Wed	47	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 09:50	10.59	84%	115.3°
2047-02-07 Thu	47	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 09:45	10.55	91%	117.3°
2047-02-08 Fri	43	—	unknown	04:00–05:55 (good, 1.92 h)	87.1° 09:40	10.52	96%	117.8°
2047-02-09 Sat	41	—	unknown	04:00–05:50 (good, 1.83 h)	87.1° 09:40	10.48	99%	116.5°
2047-02-10 Sun	40	—	unknown	04:00–05:50 (good, 1.83 h)	87.1° 09:35	10.44	100%	113.4°
2047-02-11 Mon	38	—	unknown	04:00–05:50 (good, 1.83 h)	87.1° 09:30	10.41	98%	108.9°
2047-02-12 Tue	37	—	unknown	03:55–05:50 (good, 1.92 h)	87.1° 09:25	10.37	92%	103.2°
2047-02-13 Wed	36	—	unknown	03:55–05:45 (good, 1.83 h)	87.1° 09:25	10.33	85%	96.7°
2047-02-14 Thu	37	—	unknown	03:50–05:45 (good, 1.92 h)	87.1° 09:20	10.29	76%	90.0°
2047-02-15 Fri	39	—	unknown	03:40–05:45 (good, 2.08 h)	87.1° 09:15	10.25	65%	83.3°
2047-02-16 Sat	43	—	unknown	03:35–05:45 (good, 2.17 h)	87.1° 09:10	10.21	54%	77.1°
2047-02-17 Sun	46	—	unknown	03:25–05:40 (good, 2.25 h)	87.1° 09:05	10.17	43%	71.6°
2047-02-18 Mon	53	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:05	10.13	32%	67.2°
2047-02-19 Tue	58	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 09:00	10.09	22%	64.1°
2047-02-20 Wed	64	—	unknown	03:00–05:40 (good, 2.67 h)	87.1° 08:55	10.04	14%	62.4°
2047-02-21 Thu	67	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:50	10.0	8%	62.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-01-23&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.