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: 02-17 (63), 02-18 (63), 02-16 (62), 02-15 (60), 02-13 (59) — by astronomy; check the weather when the night is within four days.

2048-01-20astronomy score per night — click a bar for that night2048-02-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2048-01-20 Mon	30	—	unknown	05:05–06:10 (good, 1.08 h)	87.1° 11:00	11.12	31%	82.1°
2048-01-21 Tue	30	—	unknown	05:00–06:05 (good, 1.08 h)	87.1° 10:55	11.09	41%	88.1°
2048-01-22 Wed	31	—	unknown	04:55–06:05 (good, 1.17 h)	87.1° 10:50	11.06	50%	94.0°
2048-01-23 Thu	33	—	unknown	04:50–06:05 (good, 1.25 h)	87.1° 10:45	11.04	60%	99.7°
2048-01-24 Fri	34	—	unknown	04:50–06:05 (good, 1.25 h)	87.1° 10:40	11.01	69%	105.1°
2048-01-25 Sat	35	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:40	10.98	77%	109.9°
2048-01-26 Sun	35	—	unknown	04:50–06:05 (good, 1.25 h)	87.1° 10:35	10.95	84%	114.0°
2048-01-27 Mon	35	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:30	10.92	91%	117.1°
2048-01-28 Tue	33	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:25	10.89	96%	119.0°
2048-01-29 Wed	32	—	unknown	04:40–06:00 (good, 1.33 h)	87.1° 10:25	10.86	99%	119.5°
2048-01-30 Thu	32	—	unknown	04:40–06:00 (good, 1.33 h)	87.1° 10:20	10.83	100%	118.3°
2048-01-31 Fri	31	—	unknown	04:35–06:00 (good, 1.42 h)	87.1° 10:15	10.8	99%	115.6°
2048-02-01 Sat	30	—	unknown	04:35–06:00 (good, 1.42 h)	87.1° 10:10	10.77	96%	111.5°
2048-02-02 Sun	30	—	unknown	04:35–06:00 (good, 1.42 h)	87.1° 10:05	10.74	90%	106.3°
2048-02-03 Mon	30	—	unknown	04:30–06:00 (good, 1.5 h)	87.1° 10:05	10.7	83%	100.2°
2048-02-04 Tue	30	—	unknown	04:30–05:55 (good, 1.42 h)	87.1° 10:00	10.67	74%	93.6°
2048-02-05 Wed	31	—	unknown	04:20–05:55 (good, 1.58 h)	87.1° 09:55	10.63	63%	86.7°
2048-02-06 Thu	34	—	unknown	04:15–05:55 (good, 1.67 h)	87.1° 09:50	10.6	52%	80.0°
2048-02-07 Fri	38	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 09:45	10.56	41%	73.7°
2048-02-08 Sat	43	—	unknown	03:55–05:55 (good, 2.0 h)	87.1° 09:45	10.53	30%	68.2°
2048-02-09 Sun	47	—	unknown	03:45–05:50 (good, 2.08 h)	87.1° 09:40	10.49	20%	63.9°
2048-02-10 Mon	52	—	unknown	03:40–05:50 (good, 2.17 h)	87.1° 09:35	10.45	12%	61.2°
2048-02-11 Tue	55	—	unknown	03:35–05:50 (good, 2.25 h)	87.1° 09:30	10.41	5%	60.5°
2048-02-12 Wed	57	—	unknown	03:35–05:50 (good, 2.25 h)	87.1° 09:25	10.38	2%	61.7°
2048-02-13 Thu	59	—	unknown	03:30–05:50 (good, 2.33 h)	87.1° 09:25	10.34	0%	64.6°
2048-02-14 Fri	58	—	unknown	03:25–05:45 (good, 2.33 h)	87.1° 09:20	10.3	1%	68.9°
2048-02-15 Sat	60	—	unknown	03:20–05:45 (good, 2.42 h)	87.1° 09:15	10.26	4%	74.2°
2048-02-16 Sun	62	—	unknown	03:15–05:45 (good, 2.5 h)	87.1° 09:10	10.22	10%	80.0°
2048-02-17 Mon	63	—	unknown	03:15–05:45 (good, 2.5 h)	87.1° 09:10	10.18	16%	86.0°
2048-02-18 Tue	63	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:05	10.14	24%	92.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-01-20&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.