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 (52), 04-02 (52), 03-30 (51), 03-31 (51), 04-03 (51) — by astronomy; check the weather when the night is within four days.

2039-03-05astronomy score per night — click a bar for that night2039-04-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-03-05 Sat	30	—	unknown	04:15–05:20 (good, 1.08 h)	87.3° 10:25	9.47	76%	107.6°
2039-03-06 Sun	29	—	unknown	04:20–05:15 (good, 0.92 h)	87.3° 10:20	9.42	84%	111.9°
2039-03-07 Mon	26	—	unknown	04:15–05:15 (good, 1.0 h)	87.2° 10:20	9.38	91%	115.2°
2039-03-08 Tue	26	—	unknown	04:15–05:15 (good, 1.0 h)	87.3° 10:15	9.33	96%	117.3°
2039-03-09 Wed	26	—	unknown	04:10–05:10 (good, 1.0 h)	87.3° 10:10	9.28	99%	117.8°
2039-03-10 Thu	26	—	unknown	04:10–05:10 (good, 1.0 h)	87.3° 10:05	9.23	100%	116.5°
2039-03-11 Fri	25	—	unknown	04:05–05:10 (good, 1.08 h)	87.3° 10:00	9.18	98%	113.5°
2039-03-12 Sat	24	—	unknown	04:05–05:05 (good, 1.0 h)	87.3° 10:00	9.13	93%	109.1°
2039-03-13 Sun	24	—	unknown	04:05–05:05 (good, 1.0 h)	87.3° 09:55	9.08	86%	103.4°
2039-03-14 Mon	25	—	unknown	04:00–05:05 (good, 1.08 h)	87.3° 09:50	9.03	77%	97.1°
2039-03-15 Tue	26	—	unknown	03:55–05:00 (good, 1.08 h)	87.3° 09:45	8.98	67%	90.5°
2039-03-16 Wed	28	—	unknown	03:45–05:00 (good, 1.25 h)	87.2° 09:40	8.93	56%	83.9°
2039-03-17 Thu	30	—	unknown	03:35–05:00 (good, 1.42 h)	87.3° 09:40	8.88	44%	77.7°
2039-03-18 Fri	34	—	unknown	03:20–04:55 (good, 1.58 h)	87.3° 09:35	8.83	33%	72.2°
2039-03-19 Sat	39	—	unknown	03:15–04:55 (good, 1.67 h)	87.3° 09:30	8.78	24%	67.7°
2039-03-20 Sun	43	—	unknown	03:10–04:55 (good, 1.75 h)	87.3° 09:25	8.73	15%	64.4°
2039-03-21 Mon	43	—	unknown	03:10–04:50 (good, 1.67 h)	87.2° 09:25	8.68	8%	62.5°
2039-03-22 Tue	44	—	unknown	03:05–04:50 (good, 1.75 h)	87.3° 09:20	8.63	4%	62.3°
2039-03-23 Wed	44	—	unknown	03:00–04:45 (good, 1.75 h)	87.3° 09:15	8.57	1%	63.5°
2039-03-24 Thu	46	—	unknown	02:55–04:45 (good, 1.83 h)	87.3° 09:10	8.52	0%	66.0°
2039-03-25 Fri	47	—	unknown	02:50–04:45 (good, 1.92 h)	87.3° 09:05	8.47	2%	69.7°
2039-03-26 Sat	47	—	unknown	02:50–05:40 (good, 1.83 h)	87.3° 10:05	8.42	5%	74.1°
2039-03-27 Sun	48	—	unknown	03:45–05:40 (good, 1.92 h)	87.3° 10:00	8.36	10%	79.1°
2039-03-28 Mon	48	—	unknown	03:40–05:35 (good, 1.92 h)	87.3° 09:55	8.31	16%	84.4°
2039-03-29 Tue	50	—	unknown	03:35–05:35 (good, 2.0 h)	87.3° 09:50	8.25	23%	89.9°
2039-03-30 Wed	51	—	unknown	03:30–05:35 (good, 2.08 h)	87.2° 09:45	8.2	32%	95.3°
2039-03-31 Thu	51	—	unknown	03:30–05:30 (good, 2.0 h)	87.3° 09:45	8.15	41%	100.7°
2039-04-01 Fri	52	—	unknown	03:25–05:30 (good, 2.08 h)	87.3° 09:40	8.09	50%	105.7°
2039-04-02 Sat	52	—	unknown	03:30–05:30 (good, 2.0 h)	87.3° 09:35	8.04	60%	110.1°
2039-04-03 Sun	51	—	unknown	03:25–05:25 (good, 2.0 h)	87.3° 09:30	7.98	70%	113.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-03-05&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.