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: 02-20 (63), 02-19 (57), 02-18 (52), 02-06 (48), 02-05 (47) — by astronomy; check the weather when the night is within four days.

2028-01-22astronomy score per night — click a bar for that night2028-02-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-01-22 Sat	29	—	unknown	04:55–06:05 (good, 1.17 h)	87.1° 10:50	11.07	12%	67.7°
2028-01-23 Sun	32	—	unknown	04:50–06:05 (good, 1.25 h)	87.1° 10:45	11.04	7%	64.9°
2028-01-24 Mon	34	—	unknown	04:50–06:05 (good, 1.25 h)	87.1° 10:40	11.01	3%	63.2°
2028-01-25 Tue	35	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:40	10.99	0%	62.9°
2028-01-26 Wed	36	—	unknown	04:40–06:05 (good, 1.42 h)	87.1° 10:35	10.96	0%	63.8°
2028-01-27 Thu	37	—	unknown	04:35–06:05 (good, 1.5 h)	87.1° 10:30	10.93	2%	65.9°
2028-01-28 Fri	39	—	unknown	04:30–06:05 (good, 1.58 h)	87.1° 10:25	10.9	5%	69.0°
2028-01-29 Sat	40	—	unknown	04:30–06:00 (good, 1.5 h)	87.1° 10:20	10.87	10%	73.0°
2028-01-30 Sun	40	—	unknown	04:25–06:00 (good, 1.58 h)	87.1° 10:20	10.84	16%	77.6°
2028-01-31 Mon	42	—	unknown	04:20–06:00 (good, 1.67 h)	87.1° 10:15	10.81	23%	82.8°
2028-02-01 Tue	44	—	unknown	04:15–06:00 (good, 1.75 h)	87.1° 10:10	10.77	32%	88.2°
2028-02-02 Wed	45	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:05	10.74	41%	93.8°
2028-02-03 Thu	46	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:05	10.71	51%	99.4°
2028-02-04 Fri	46	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 10:00	10.67	62%	104.8°
2028-02-05 Sat	47	—	unknown	04:00–05:55 (good, 1.92 h)	87.1° 09:55	10.64	72%	109.7°
2028-02-06 Sun	48	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 09:50	10.6	81%	113.6°
2028-02-07 Mon	47	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 09:45	10.57	90%	116.3°
2028-02-08 Tue	42	—	unknown	04:00–05:55 (good, 1.92 h)	87.1° 09:45	10.53	96%	117.2°
2028-02-09 Wed	40	—	unknown	04:00–05:50 (good, 1.83 h)	87.1° 09:40	10.49	99%	116.1°
2028-02-10 Thu	39	—	unknown	04:00–05:50 (good, 1.83 h)	87.1° 09:35	10.46	100%	113.0°
2028-02-11 Fri	38	—	unknown	04:00–05:50 (good, 1.83 h)	87.1° 09:30	10.42	97%	108.3°
2028-02-12 Sat	37	—	unknown	04:00–05:50 (good, 1.83 h)	87.1° 09:25	10.38	92%	102.6°
2028-02-13 Sun	36	—	unknown	03:55–05:50 (good, 1.92 h)	87.1° 09:25	10.34	84%	96.2°
2028-02-14 Mon	37	—	unknown	03:50–05:45 (good, 1.92 h)	87.1° 09:20	10.3	75%	89.8°
2028-02-15 Tue	39	—	unknown	03:45–05:45 (good, 2.0 h)	87.1° 09:15	10.27	65%	83.5°
2028-02-16 Wed	42	—	unknown	03:35–05:45 (good, 2.17 h)	87.1° 09:10	10.23	54%	77.7°
2028-02-17 Thu	47	—	unknown	03:25–05:45 (good, 2.33 h)	87.1° 09:10	10.18	44%	72.7°
2028-02-18 Fri	52	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:05	10.14	34%	68.5°
2028-02-19 Sat	57	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 09:00	10.1	25%	65.4°
2028-02-20 Sun	63	—	unknown	03:00–05:40 (good, 2.67 h)	87.1° 08:55	10.06	17%	63.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-01-22&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.