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 (30), 01-21 (30), 01-19 (28), 01-18 (27), 01-17 (25) — by astronomy; check the weather when the night is within four days.

2031-12-23astronomy score per night — click a bar for that night2032-01-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-12-23 Tue	9	—	unknown	18:40–19:25 (marginal, 0.75 h)	87.1° 12:50	11.51	79%	99.5°
2031-12-24 Wed	8	—	unknown	18:40–19:20 (marginal, 0.67 h)	87.1° 12:50	11.5	87%	105.9°
2031-12-25 Thu	8	—	unknown	18:40–19:15 (marginal, 0.58 h)	87.1° 12:45	11.5	93%	111.6°
2031-12-26 Fri	8	—	unknown	18:40–19:10 (marginal, 0.5 h)	87.1° 12:40	11.5	97%	116.3°
2031-12-27 Sat	8	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:35	11.49	99%	119.9°
2031-12-28 Sun	8	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:30	11.49	100%	122.1°
2031-12-29 Mon	8	—	unknown	18:40–19:00 (marginal, 0.33 h)	87.1° 12:30	11.48	98%	122.7°
2031-12-30 Tue	8	—	unknown	18:40–18:55 (marginal, 0.25 h)	87.1° 12:25	11.47	96%	121.7°
2031-12-31 Wed	7	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.46	91%	119.2°
2032-01-01 Thu	7	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.45	85%	115.5°
2032-01-02 Fri	7	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.44	77%	110.7°
2032-01-03 Sat	8	—	unknown	05:40–06:10 (marginal, 0.5 h)	87.1° 12:10	11.43	69%	105.2°
2032-01-04 Sun	8	—	unknown	05:35–06:10 (marginal, 0.58 h)	87.1° 12:05	11.42	60%	99.0°
2032-01-05 Mon	9	—	unknown	05:30–06:10 (marginal, 0.67 h)	87.1° 12:00	11.41	50%	92.4°
2032-01-06 Tue	10	—	unknown	05:25–06:45 (marginal, 1.33 h)	87.1° 11:55	11.39	40%	85.5°
2032-01-07 Wed	11	—	unknown	06:05–06:10 (good, 0.08 h)	87.1° 11:50	11.38	30%	78.6°
2032-01-08 Thu	13	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:45	11.36	20%	71.8°
2032-01-09 Fri	15	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:40	11.35	12%	65.8°
2032-01-10 Sat	18	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:35	11.33	5%	60.9°
2032-01-11 Sun	19	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:35	11.31	1%	58.0°
2032-01-12 Mon	20	—	unknown	05:35–06:10 (good, 0.58 h)	87.1° 11:30	11.3	0%	57.4°
2032-01-13 Tue	21	—	unknown	05:30–06:10 (good, 0.67 h)	87.1° 11:25	11.28	2%	59.4°
2032-01-14 Wed	23	—	unknown	05:25–06:10 (good, 0.75 h)	87.1° 11:20	11.26	7%	63.6°
2032-01-15 Thu	24	—	unknown	05:25–06:10 (good, 0.75 h)	87.1° 11:20	11.23	14%	69.5°
2032-01-16 Fri	24	—	unknown	05:20–06:10 (good, 0.83 h)	87.1° 11:15	11.21	23%	76.4°
2032-01-17 Sat	25	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 11:10	11.19	33%	83.7°
2032-01-18 Sun	27	—	unknown	05:10–06:10 (good, 1.0 h)	87.1° 11:05	11.17	44%	91.0°
2032-01-19 Mon	28	—	unknown	05:10–06:10 (good, 1.0 h)	87.1° 11:00	11.14	55%	98.1°
2032-01-20 Tue	30	—	unknown	05:05–06:10 (good, 1.08 h)	87.1° 11:00	11.12	65%	104.7°
2032-01-21 Wed	30	—	unknown	05:00–06:05 (good, 1.08 h)	87.1° 10:55	11.09	74%	110.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-12-23&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.