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 V1057 Cyg: 04-01 (54), 04-04 (54), 04-03 (53), 04-05 (53), 03-31 (52) — by astronomy; check the weather when the night is within four days.

2028-03-15astronomy score per night — click a bar for that night2028-04-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-03-15 Wed	28	—	unknown	03:45–05:00 (good, 1.25 h)	87.3° 09:45	8.95	70%	97.9°
2028-03-16 Thu	29	—	unknown	03:40–05:00 (good, 1.33 h)	87.3° 09:40	8.9	60%	90.3°
2028-03-17 Fri	30	—	unknown	03:35–04:55 (good, 1.33 h)	87.3° 09:35	8.85	50%	82.8°
2028-03-18 Sat	33	—	unknown	03:30–04:55 (good, 1.42 h)	87.3° 09:30	8.8	41%	75.8°
2028-03-19 Sun	36	—	unknown	03:15–04:55 (good, 1.67 h)	87.3° 09:30	8.75	31%	69.4°
2028-03-20 Mon	39	—	unknown	03:10–04:50 (good, 1.67 h)	87.3° 09:25	8.7	23%	63.8°
2028-03-21 Tue	43	—	unknown	03:05–04:50 (good, 1.75 h)	87.3° 09:20	8.64	16%	59.3°
2028-03-22 Wed	45	—	unknown	03:00–04:50 (good, 1.83 h)	87.3° 09:15	8.59	9%	56.0°
2028-03-23 Thu	45	—	unknown	02:55–04:45 (good, 1.83 h)	87.3° 09:10	8.54	5%	54.3°
2028-03-24 Fri	46	—	unknown	02:55–04:45 (good, 1.83 h)	87.3° 09:10	8.49	2%	54.3°
2028-03-25 Sat	46	—	unknown	02:50–05:40 (good, 1.83 h)	87.3° 10:05	8.43	0%	56.1°
2028-03-26 Sun	48	—	unknown	03:45–05:40 (good, 1.92 h)	87.3° 10:00	8.38	1%	59.5°
2028-03-27 Mon	49	—	unknown	03:40–05:40 (good, 2.0 h)	87.3° 09:55	8.33	3%	64.4°
2028-03-28 Tue	50	—	unknown	03:35–05:35 (good, 2.0 h)	87.3° 09:50	8.27	7%	70.3°
2028-03-29 Wed	50	—	unknown	03:35–05:35 (good, 2.0 h)	87.3° 09:50	8.22	13%	77.1°
2028-03-30 Thu	50	—	unknown	03:30–05:30 (good, 2.0 h)	87.3° 09:45	8.16	21%	84.4°
2028-03-31 Fri	52	—	unknown	03:25–05:30 (good, 2.08 h)	87.3° 09:40	8.11	30%	92.0°
2028-04-01 Sat	54	—	unknown	03:20–05:30 (good, 2.17 h)	87.3° 09:35	8.05	40%	99.8°
2028-04-02 Sun	52	—	unknown	03:20–05:25 (good, 2.08 h)	87.3° 09:30	8.0	51%	107.3°
2028-04-03 Mon	53	—	unknown	03:20–05:25 (good, 2.08 h)	87.3° 09:30	7.94	63%	114.3°
2028-04-04 Tue	54	—	unknown	03:20–05:25 (good, 2.08 h)	87.3° 09:25	7.89	73%	120.2°
2028-04-05 Wed	53	—	unknown	03:15–05:20 (good, 2.08 h)	87.3° 09:20	7.83	83%	124.3°
2028-04-06 Thu	49	—	unknown	03:15–05:20 (good, 2.08 h)	87.3° 09:15	7.78	91%	126.0°
2028-04-07 Fri	47	—	unknown	03:10–05:15 (good, 2.08 h)	87.3° 09:15	7.72	97%	125.0°
2028-04-08 Sat	47	—	unknown	03:10–05:15 (good, 2.08 h)	87.3° 09:10	7.66	100%	121.3°
2028-04-09 Sun	46	—	unknown	03:05–05:15 (good, 2.17 h)	87.3° 09:05	7.61	100%	115.6°
2028-04-10 Mon	43	—	unknown	03:05–05:10 (good, 2.08 h)	87.3° 09:00	7.55	97%	108.6°
2028-04-11 Tue	41	—	unknown	03:05–05:10 (good, 2.08 h)	87.3° 08:55	7.49	92%	100.9°
2028-04-12 Wed	40	—	unknown	03:05–05:05 (good, 2.0 h)	87.3° 08:55	7.44	85%	93.1°
2028-04-13 Thu	40	—	unknown	03:00–05:05 (good, 2.08 h)	87.3° 08:50	7.38	76%	85.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-03-15&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.