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: 01-13 (22), 01-12 (21), 12-15 (20), 01-11 (20), 12-16 (18) — by astronomy; check the weather when the night is within four days.

2034-12-15astronomy score per night — click a bar for that night2035-01-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-12-15 Fri	20	—	unknown	18:35–19:15 (good, 0.67 h)	87.1° 13:20	11.49	22%	65.0°
2034-12-16 Sat	18	—	unknown	18:35–19:05 (good, 0.5 h)	87.1° 13:20	11.5	31%	70.3°
2034-12-17 Sun	16	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 13:15	11.5	41%	76.5°
2034-12-18 Mon	14	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:10	11.5	52%	83.4°
2034-12-19 Tue	13	—	unknown	18:35–18:40 (good, 0.08 h)	87.1° 13:05	11.51	63%	90.8°
2034-12-20 Wed	12	—	unknown	18:35–18:40 (good, 0.08 h)	87.1° 13:05	11.51	74%	98.4°
2034-12-21 Thu	11	—	unknown	18:05–19:30 (marginal, 1.42 h)	87.1° 13:00	11.51	83%	105.8°
2034-12-22 Fri	11	—	unknown	18:05–19:25 (marginal, 1.33 h)	87.1° 12:55	11.51	91%	112.5°
2034-12-23 Sat	10	—	unknown	18:40–19:20 (marginal, 0.67 h)	87.1° 12:50	11.51	97%	118.0°
2034-12-24 Sun	10	—	unknown	18:40–19:20 (marginal, 0.67 h)	87.1° 12:45	11.5	100%	121.6°
2034-12-25 Mon	9	—	unknown	18:40–19:15 (marginal, 0.58 h)	87.1° 12:45	11.5	99%	122.8°
2034-12-26 Tue	9	—	unknown	18:05–19:10 (marginal, 1.08 h)	87.1° 12:40	11.5	96%	121.5°
2034-12-27 Wed	10	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:35	11.49	91%	118.0°
2034-12-28 Thu	9	—	unknown	18:40–19:00 (marginal, 0.33 h)	87.1° 12:30	11.48	83%	113.0°
2034-12-29 Fri	8	—	unknown	18:40–19:00 (marginal, 0.33 h)	87.1° 12:25	11.48	74%	106.9°
2034-12-30 Sat	7	—	unknown	18:40–18:55 (marginal, 0.25 h)	87.1° 12:25	11.47	65%	100.3°
2034-12-31 Sun	6	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.46	55%	93.6°
2035-01-01 Mon	7	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.45	45%	86.9°
2035-01-02 Tue	8	—	unknown	05:40–06:10 (marginal, 0.5 h)	87.1° 12:10	11.44	36%	80.5°
2035-01-03 Wed	9	—	unknown	05:40–06:10 (marginal, 0.5 h)	87.1° 12:10	11.43	27%	74.4°
2035-01-04 Thu	10	—	unknown	05:35–06:45 (marginal, 1.17 h)	87.1° 12:00	11.42	19%	68.9°
2035-01-05 Fri	11	—	unknown	06:05–06:10 (good, 0.08 h)	87.1° 12:00	11.4	12%	64.2°
2035-01-06 Sat	13	—	unknown	06:00–06:10 (good, 0.17 h)	87.1° 11:50	11.39	7%	60.5°
2035-01-07 Sun	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:50	11.38	3%	58.1°
2035-01-08 Mon	15	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:45	11.36	1%	57.2°
2035-01-09 Tue	16	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:40	11.34	0%	57.9°
2035-01-10 Wed	18	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:35	11.33	2%	60.3°
2035-01-11 Thu	20	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:30	11.31	5%	64.1°
2035-01-12 Fri	21	—	unknown	05:35–06:10 (good, 0.58 h)	87.1° 11:30	11.29	11%	69.2°
2035-01-13 Sat	22	—	unknown	05:30–06:10 (good, 0.67 h)	87.1° 11:25	11.27	18%	75.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-12-15&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.