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: 12-18 (20), 12-19 (20), 12-20 (18), 01-16 (17), 12-21 (16) — by astronomy; check the weather when the night is within four days.

2046-12-18astronomy score per night — click a bar for that night2047-01-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-12-18 Tue	20	—	unknown	18:35–19:10 (good, 0.58 h)	87.1° 13:10	11.5	69%	110.8°
2046-12-19 Wed	20	—	unknown	18:35–19:05 (good, 0.5 h)	87.1° 13:05	11.51	58%	105.8°
2046-12-20 Thu	18	—	unknown	18:35–19:00 (good, 0.42 h)	87.1° 13:05	11.51	46%	99.9°
2046-12-21 Fri	16	—	unknown	18:35–19:00 (good, 0.42 h)	87.1° 13:00	11.51	35%	93.5°
2046-12-22 Sat	15	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 12:55	11.51	25%	86.9°
2046-12-23 Sun	13	—	unknown	18:40–18:50 (good, 0.17 h)	87.1° 12:50	11.51	15%	80.4°
2046-12-24 Mon	12	—	unknown	18:40–18:45 (good, 0.08 h)	87.1° 12:45	11.5	8%	74.3°
2046-12-25 Tue	11	—	unknown	18:05–19:15 (marginal, 1.17 h)	87.1° 12:45	11.5	3%	69.2°
2046-12-26 Wed	11	—	unknown	18:05–19:10 (marginal, 1.08 h)	87.1° 12:40	11.5	0%	65.3°
2046-12-27 Thu	10	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:35	11.49	0%	62.9°
2046-12-28 Fri	9	—	unknown	18:40–19:00 (marginal, 0.33 h)	87.1° 12:30	11.48	3%	62.2°
2046-12-29 Sat	9	—	unknown	18:40–19:00 (marginal, 0.33 h)	87.1° 12:25	11.48	7%	63.1°
2046-12-30 Sun	8	—	unknown	05:55–06:10 (marginal, 0.25 h)	87.1° 12:25	11.47	13%	65.3°
2046-12-31 Mon	8	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.46	20%	68.8°
2047-01-01 Tue	9	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.45	29%	73.0°
2047-01-02 Wed	10	—	unknown	05:40–06:10 (marginal, 0.5 h)	87.1° 12:10	11.44	38%	77.9°
2047-01-03 Thu	10	—	unknown	05:40–06:45 (marginal, 1.08 h)	87.1° 12:10	11.43	47%	83.1°
2047-01-04 Fri	11	—	unknown	06:05–06:10 (good, 0.08 h)	87.1° 12:00	11.42	57%	88.6°
2047-01-05 Sat	12	—	unknown	06:00–06:10 (good, 0.17 h)	87.1° 12:00	11.4	66%	94.1°
2047-01-06 Sun	13	—	unknown	06:00–06:10 (good, 0.17 h)	87.1° 11:50	11.39	75%	99.5°
2047-01-07 Mon	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:50	11.37	83%	104.7°
2047-01-08 Tue	15	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:45	11.36	90%	109.4°
2047-01-09 Wed	13	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:40	11.34	95%	113.4°
2047-01-10 Thu	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:35	11.33	98%	116.2°
2047-01-11 Fri	15	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:30	11.31	100%	117.7°
2047-01-12 Sat	16	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:30	11.29	99%	117.5°
2047-01-13 Sun	16	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:25	11.27	96%	115.5°
2047-01-14 Mon	16	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:20	11.25	90%	112.0°
2047-01-15 Tue	16	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:15	11.23	82%	107.1°
2047-01-16 Wed	17	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:15	11.21	72%	101.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-12-18&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.