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: 01-20 (20), 01-11 (19), 01-19 (18), 01-10 (17), 01-14 (17) — by astronomy; check the weather when the night is within four days.

2043-12-22astronomy score per night — click a bar for that night2044-01-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-12-22 Tue	15	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 12:55	11.51	53%	98.5°
2043-12-23 Wed	13	—	unknown	18:40–18:50 (good, 0.17 h)	87.1° 12:50	11.51	43%	93.6°
2043-12-24 Thu	12	—	unknown	18:40–18:45 (good, 0.08 h)	87.1° 12:50	11.5	33%	88.7°
2043-12-25 Fri	11	—	unknown	18:40–18:45 (good, 0.08 h)	87.1° 12:45	11.5	25%	84.0°
2043-12-26 Sat	11	—	unknown	18:05–19:10 (marginal, 1.08 h)	87.1° 12:40	11.5	17%	79.5°
2043-12-27 Sun	10	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:35	11.49	11%	75.4°
2043-12-28 Mon	10	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:30	11.49	6%	71.9°
2043-12-29 Tue	9	—	unknown	18:40–19:00 (marginal, 0.33 h)	87.1° 12:30	11.48	2%	69.1°
2043-12-30 Wed	8	—	unknown	18:40–18:55 (marginal, 0.25 h)	87.1° 12:25	11.47	0%	67.2°
2043-12-31 Thu	8	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.46	0%	66.4°
2044-01-01 Fri	9	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.45	2%	66.6°
2044-01-02 Sat	9	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.44	6%	67.9°
2044-01-03 Sun	10	—	unknown	05:40–06:45 (marginal, 1.08 h)	87.1° 12:10	11.43	11%	70.3°
2044-01-04 Mon	11	—	unknown	06:05–06:10 (good, 0.08 h)	87.1° 12:05	11.42	18%	73.6°
2044-01-05 Tue	12	—	unknown	06:05–06:10 (good, 0.08 h)	87.1° 12:00	11.41	27%	77.8°
2044-01-06 Wed	13	—	unknown	06:00–06:10 (good, 0.17 h)	87.1° 11:55	11.39	37%	82.6°
2044-01-07 Thu	13	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:50	11.38	47%	87.9°
2044-01-08 Fri	15	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:45	11.36	58%	93.4°
2044-01-09 Sat	16	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:40	11.35	69%	98.8°
2044-01-10 Sun	17	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:35	11.33	80%	104.0°
2044-01-11 Mon	19	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:35	11.31	88%	108.4°
2044-01-12 Tue	16	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:30	11.29	95%	111.7°
2044-01-13 Wed	16	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:25	11.27	99%	113.4°
2044-01-14 Thu	17	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:20	11.25	100%	113.5°
2044-01-15 Fri	17	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:20	11.23	98%	112.0°
2044-01-16 Sat	16	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:15	11.21	94%	109.0°
2044-01-17 Sun	16	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:10	11.19	87%	105.1°
2044-01-18 Mon	17	—	unknown	05:35–06:10 (good, 0.58 h)	87.1° 11:05	11.17	79%	100.5°
2044-01-19 Tue	18	—	unknown	05:30–06:10 (good, 0.67 h)	87.1° 11:00	11.14	70%	95.5°
2044-01-20 Wed	20	—	unknown	05:25–06:10 (good, 0.75 h)	87.1° 11:00	11.12	60%	90.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-12-22&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.