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: 02-02 (33), 01-20 (30), 02-01 (30), 01-21 (29), 01-19 (28) — by astronomy; check the weather when the night is within four days.

2043-01-04astronomy score per night — click a bar for that night2043-02-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-01-04 Sun	9	—	unknown	05:35–06:10 (marginal, 0.58 h)	87.1° 12:00	11.42	34%	83.4°
2043-01-05 Mon	10	—	unknown	05:30–06:45 (marginal, 1.25 h)	87.1° 12:00	11.4	26%	79.1°
2043-01-06 Tue	12	—	unknown	06:05–06:10 (good, 0.08 h)	87.1° 11:50	11.39	18%	75.1°
2043-01-07 Wed	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:50	11.38	11%	71.7°
2043-01-08 Thu	15	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:45	11.36	6%	69.0°
2043-01-09 Fri	16	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:40	11.34	2%	67.3°
2043-01-10 Sat	18	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:35	11.33	0%	66.7°
2043-01-11 Sun	20	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:30	11.31	1%	67.4°
2043-01-12 Mon	21	—	unknown	05:35–06:10 (good, 0.58 h)	87.1° 11:30	11.29	3%	69.4°
2043-01-13 Tue	22	—	unknown	05:30–06:10 (good, 0.67 h)	87.1° 11:25	11.27	8%	72.5°
2043-01-14 Wed	23	—	unknown	05:25–06:10 (good, 0.75 h)	87.1° 11:20	11.25	15%	76.6°
2043-01-15 Thu	24	—	unknown	05:20–06:10 (good, 0.83 h)	87.1° 11:15	11.23	24%	81.5°
2043-01-16 Fri	25	—	unknown	05:20–06:10 (good, 0.83 h)	87.1° 11:15	11.21	34%	86.8°
2043-01-17 Sat	25	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 11:10	11.18	45%	92.3°
2043-01-18 Sun	27	—	unknown	05:10–06:10 (good, 1.0 h)	87.1° 11:05	11.16	56%	97.8°
2043-01-19 Mon	28	—	unknown	05:05–06:10 (good, 1.08 h)	87.1° 11:00	11.14	67%	102.8°
2043-01-20 Tue	30	—	unknown	05:05–06:10 (good, 1.08 h)	87.1° 10:55	11.11	78%	107.2°
2043-01-21 Wed	29	—	unknown	05:10–06:05 (good, 0.92 h)	87.1° 10:55	11.09	86%	110.5°
2043-01-22 Thu	25	—	unknown	05:05–06:05 (good, 1.0 h)	87.1° 10:50	11.06	93%	112.6°
2043-01-23 Fri	25	—	unknown	05:05–06:05 (good, 1.0 h)	87.1° 10:45	11.03	98%	113.3°
2043-01-24 Sat	25	—	unknown	05:05–06:05 (good, 1.0 h)	87.1° 10:40	11.0	100%	112.5°
2043-01-25 Sun	25	—	unknown	05:05–06:05 (good, 1.0 h)	87.1° 10:35	10.98	99%	110.5°
2043-01-26 Mon	24	—	unknown	05:05–06:05 (good, 1.0 h)	87.1° 10:35	10.95	97%	107.4°
2043-01-27 Tue	23	—	unknown	05:00–06:05 (good, 1.08 h)	87.1° 10:30	10.92	92%	103.5°
2043-01-28 Wed	24	—	unknown	05:00–06:05 (good, 1.08 h)	87.1° 10:25	10.89	86%	99.2°
2043-01-29 Thu	24	—	unknown	04:55–06:00 (good, 1.08 h)	87.1° 10:20	10.86	79%	94.5°
2043-01-30 Fri	26	—	unknown	04:50–06:00 (good, 1.17 h)	87.1° 10:20	10.83	70%	89.8°
2043-01-31 Sat	27	—	unknown	04:40–06:00 (good, 1.33 h)	87.1° 10:15	10.79	62%	85.2°
2043-02-01 Sun	30	—	unknown	04:35–06:00 (good, 1.42 h)	87.1° 10:10	10.76	52%	80.7°
2043-02-02 Mon	33	—	unknown	04:25–06:00 (good, 1.58 h)	87.1° 10:05	10.73	43%	76.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-01-04&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.