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: 02-16 (63), 02-15 (61), 02-14 (60), 02-12 (58), 02-13 (58) — by astronomy; check the weather when the night is within four days.

2029-01-18astronomy score per night — click a bar for that night2029-02-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-01-18 Thu	28	—	unknown	05:10–06:10 (good, 1.0 h)	87.1° 11:05	11.15	17%	72.8°
2029-01-19 Fri	29	—	unknown	05:05–06:10 (good, 1.08 h)	87.1° 11:00	11.13	24%	77.8°
2029-01-20 Sat	30	—	unknown	05:00–06:10 (good, 1.17 h)	87.1° 10:55	11.1	33%	83.3°
2029-01-21 Sun	31	—	unknown	04:55–06:05 (good, 1.17 h)	87.1° 10:50	11.08	42%	88.9°
2029-01-22 Mon	32	—	unknown	04:55–06:05 (good, 1.17 h)	87.1° 10:45	11.05	51%	94.6°
2029-01-23 Tue	34	—	unknown	04:50–06:05 (good, 1.25 h)	87.1° 10:45	11.02	61%	100.3°
2029-01-24 Wed	34	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:40	10.99	70%	105.7°
2029-01-25 Thu	36	—	unknown	04:40–06:05 (good, 1.42 h)	87.1° 10:35	10.96	79%	110.5°
2029-01-26 Fri	36	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:30	10.94	87%	114.6°
2029-01-27 Sat	33	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:25	10.91	93%	117.5°
2029-01-28 Sun	33	—	unknown	04:40–06:05 (good, 1.42 h)	87.1° 10:25	10.88	98%	118.8°
2029-01-29 Mon	32	—	unknown	04:40–06:00 (good, 1.33 h)	87.1° 10:20	10.84	100%	118.2°
2029-01-30 Tue	31	—	unknown	04:40–06:00 (good, 1.33 h)	87.1° 10:15	10.81	99%	115.7°
2029-01-31 Wed	31	—	unknown	04:35–06:00 (good, 1.42 h)	87.1° 10:10	10.78	96%	111.5°
2029-02-01 Thu	30	—	unknown	04:35–06:00 (good, 1.42 h)	87.1° 10:10	10.75	90%	105.9°
2029-02-02 Fri	29	—	unknown	04:35–06:00 (good, 1.42 h)	87.1° 10:05	10.71	82%	99.5°
2029-02-03 Sat	31	—	unknown	04:30–06:00 (good, 1.5 h)	87.1° 10:00	10.68	72%	92.6°
2029-02-04 Sun	32	—	unknown	04:20–05:55 (good, 1.58 h)	87.1° 09:55	10.65	61%	85.8°
2029-02-05 Mon	35	—	unknown	04:15–05:55 (good, 1.67 h)	87.1° 09:50	10.61	50%	79.2°
2029-02-06 Tue	39	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 09:50	10.58	39%	73.3°
2029-02-07 Wed	43	—	unknown	03:50–05:55 (good, 2.08 h)	87.1° 09:45	10.54	28%	68.3°
2029-02-08 Thu	48	—	unknown	03:45–05:55 (good, 2.17 h)	87.1° 09:40	10.5	19%	64.5°
2029-02-09 Fri	52	—	unknown	03:40–05:50 (good, 2.17 h)	87.1° 09:35	10.47	12%	62.0°
2029-02-10 Sat	55	—	unknown	03:40–05:50 (good, 2.17 h)	87.1° 09:30	10.43	6%	61.1°
2029-02-11 Sun	57	—	unknown	03:35–05:50 (good, 2.25 h)	87.1° 09:30	10.39	2%	61.8°
2029-02-12 Mon	58	—	unknown	03:30–05:50 (good, 2.33 h)	87.1° 09:25	10.35	0%	63.9°
2029-02-13 Tue	58	—	unknown	03:25–05:45 (good, 2.33 h)	87.1° 09:20	10.31	0%	67.2°
2029-02-14 Wed	60	—	unknown	03:20–05:45 (good, 2.42 h)	87.1° 09:15	10.27	2%	71.4°
2029-02-15 Thu	61	—	unknown	03:20–05:45 (good, 2.42 h)	87.1° 09:15	10.23	6%	76.3°
2029-02-16 Fri	63	—	unknown	03:15–05:45 (good, 2.5 h)	87.1° 09:10	10.19	11%	81.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-01-18&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.