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: 02-08 (53), 02-09 (53), 02-07 (51), 02-05 (49), 02-06 (49) — by astronomy; check the weather when the night is within four days.

2038-01-11astronomy score per night — click a bar for that night2038-02-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-01-11 Mon	20	—	unknown	05:35–06:10 (good, 0.58 h)	87.1° 11:30	11.3	35%	89.4°
2038-01-12 Tue	21	—	unknown	05:35–06:10 (good, 0.58 h)	87.1° 11:25	11.28	44%	95.2°
2038-01-13 Wed	22	—	unknown	05:30–06:10 (good, 0.67 h)	87.1° 11:25	11.27	54%	100.7°
2038-01-14 Thu	23	—	unknown	05:25–06:10 (good, 0.75 h)	87.1° 11:20	11.24	63%	106.0°
2038-01-15 Fri	24	—	unknown	05:20–06:10 (good, 0.83 h)	87.1° 11:15	11.22	72%	110.7°
2038-01-16 Sat	25	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 11:10	11.2	81%	114.7°
2038-01-17 Sun	26	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 11:10	11.18	88%	117.5°
2038-01-18 Mon	25	—	unknown	05:20–06:10 (good, 0.83 h)	87.1° 11:05	11.15	94%	119.0°
2038-01-19 Tue	23	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 11:00	11.13	98%	118.8°
2038-01-20 Wed	23	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 10:55	11.11	100%	116.8°
2038-01-21 Thu	22	—	unknown	05:15–06:05 (good, 0.83 h)	87.1° 10:50	11.08	99%	113.1°
2038-01-22 Fri	21	—	unknown	05:15–06:05 (good, 0.83 h)	87.1° 10:50	11.05	96%	107.9°
2038-01-23 Sat	20	—	unknown	05:15–06:05 (good, 0.83 h)	87.1° 10:45	11.03	90%	101.8°
2038-01-24 Sun	20	—	unknown	05:15–06:05 (good, 0.83 h)	87.1° 10:40	11.0	82%	95.0°
2038-01-25 Mon	21	—	unknown	05:10–06:05 (good, 0.92 h)	87.1° 10:35	10.97	72%	88.0°
2038-01-26 Tue	22	—	unknown	05:05–06:05 (good, 1.0 h)	87.1° 10:30	10.94	61%	81.2°
2038-01-27 Wed	25	—	unknown	04:55–06:05 (good, 1.17 h)	87.1° 10:30	10.91	50%	74.9°
2038-01-28 Thu	29	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:25	10.88	39%	69.4°
2038-01-29 Fri	32	—	unknown	04:35–06:00 (good, 1.42 h)	87.1° 10:20	10.85	28%	65.1°
2038-01-30 Sat	37	—	unknown	04:20–06:00 (good, 1.67 h)	87.1° 10:15	10.82	19%	62.2°
2038-01-31 Sun	41	—	unknown	04:20–06:00 (good, 1.67 h)	87.1° 10:15	10.79	11%	60.9°
2038-02-01 Mon	43	—	unknown	04:15–06:00 (good, 1.75 h)	87.1° 10:10	10.75	6%	61.4°
2038-02-02 Tue	45	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:05	10.72	2%	63.4°
2038-02-03 Wed	47	—	unknown	04:05–06:00 (good, 1.92 h)	87.1° 10:00	10.69	0%	66.8°
2038-02-04 Thu	47	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 09:55	10.65	0%	71.2°
2038-02-05 Fri	49	—	unknown	04:00–05:55 (good, 1.92 h)	87.1° 09:55	10.62	3%	76.3°
2038-02-06 Sat	49	—	unknown	03:55–05:55 (good, 2.0 h)	87.1° 09:50	10.58	7%	81.8°
2038-02-07 Sun	51	—	unknown	03:50–05:55 (good, 2.08 h)	87.1° 09:45	10.55	13%	87.5°
2038-02-08 Mon	53	—	unknown	03:45–05:55 (good, 2.17 h)	87.1° 09:40	10.51	20%	93.3°
2038-02-09 Tue	53	—	unknown	03:45–05:50 (good, 2.08 h)	87.1° 09:35	10.47	28%	98.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-01-11&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.