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: 02-24 (71), 02-23 (64), 02-22 (59), 02-21 (53), 02-07 (51) — by astronomy; check the weather when the night is within four days.

2044-01-26astronomy score per night — click a bar for that night2044-02-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-01-26 Tue	36	—	unknown	04:40–06:05 (good, 1.42 h)	87.1° 10:35	10.95	10%	67.8°
2044-01-27 Wed	37	—	unknown	04:35–06:05 (good, 1.5 h)	87.1° 10:30	10.93	5%	66.5°
2044-01-28 Thu	39	—	unknown	04:30–06:05 (good, 1.58 h)	87.1° 10:25	10.9	2%	66.4°
2044-01-29 Fri	40	—	unknown	04:30–06:00 (good, 1.5 h)	87.1° 10:25	10.86	0%	67.4°
2044-01-30 Sat	40	—	unknown	04:25–06:00 (good, 1.58 h)	87.1° 10:20	10.83	1%	69.5°
2044-01-31 Sun	42	—	unknown	04:20–06:00 (good, 1.67 h)	87.1° 10:15	10.8	3%	72.6°
2044-02-01 Mon	44	—	unknown	04:15–06:00 (good, 1.75 h)	87.1° 10:10	10.77	8%	76.6°
2044-02-02 Tue	45	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:05	10.74	14%	81.3°
2044-02-03 Wed	46	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:05	10.7	22%	86.5°
2044-02-04 Thu	46	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 10:00	10.67	32%	91.9°
2044-02-05 Fri	48	—	unknown	04:00–05:55 (good, 1.92 h)	87.1° 09:55	10.63	43%	97.3°
2044-02-06 Sat	50	—	unknown	03:55–05:55 (good, 2.0 h)	87.1° 09:50	10.6	54%	102.4°
2044-02-07 Sun	51	—	unknown	03:55–05:55 (good, 2.0 h)	87.1° 09:45	10.56	65%	106.9°
2044-02-08 Mon	51	—	unknown	04:00–05:55 (good, 1.92 h)	87.1° 09:45	10.53	76%	110.5°
2044-02-09 Tue	48	—	unknown	03:55–05:50 (good, 1.92 h)	87.1° 09:40	10.49	85%	112.9°
2044-02-10 Wed	43	—	unknown	03:55–05:50 (good, 1.92 h)	87.1° 09:35	10.45	92%	113.7°
2044-02-11 Thu	41	—	unknown	03:55–05:50 (good, 1.92 h)	87.1° 09:30	10.42	98%	112.8°
2044-02-12 Fri	40	—	unknown	03:55–05:50 (good, 1.92 h)	87.1° 09:25	10.38	100%	110.5°
2044-02-13 Sat	39	—	unknown	03:55–05:50 (good, 1.92 h)	87.1° 09:25	10.34	99%	107.0°
2044-02-14 Sun	36	—	unknown	03:55–05:45 (good, 1.83 h)	87.1° 09:20	10.3	96%	102.6°
2044-02-15 Mon	36	—	unknown	03:50–05:45 (good, 1.92 h)	87.1° 09:15	10.26	92%	97.7°
2044-02-16 Tue	36	—	unknown	03:45–05:45 (good, 2.0 h)	87.1° 09:10	10.22	85%	92.6°
2044-02-17 Wed	38	—	unknown	03:40–05:45 (good, 2.08 h)	87.1° 09:10	10.18	77%	87.5°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-01-26&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.