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: 05-03 (81), 05-05 (81), 04-30 (80), 05-02 (80), 05-04 (80) — by astronomy; check the weather when the night is within four days.

2047-04-11astronomy score per night — click a bar for that night2047-05-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-04-11 Thu	43	—	unknown	03:05–05:10 (good, 2.08 h)	87.2° 09:00	7.53	96%	107.7°
2047-04-12 Fri	41	—	unknown	03:05–05:10 (good, 2.08 h)	87.2° 08:55	7.47	91%	99.3°
2047-04-13 Sat	39	—	unknown	03:00–05:05 (good, 2.08 h)	87.2° 08:50	7.41	83%	90.6°
2047-04-14 Sun	40	—	unknown	02:55–05:05 (good, 2.17 h)	87.2° 08:50	7.36	73%	82.2°
2047-04-15 Mon	42	—	unknown	02:50–05:00 (good, 2.17 h)	87.2° 08:45	7.3	63%	74.3°
2047-04-16 Tue	46	—	unknown	02:25–05:00 (good, 2.58 h)	87.2° 08:40	7.24	52%	67.4°
2047-04-17 Wed	55	—	unknown	02:20–05:00 (good, 2.67 h)	87.2° 08:35	7.18	42%	61.5°
2047-04-18 Thu	59	—	unknown	02:20–04:55 (good, 2.58 h)	87.2° 08:35	7.12	32%	57.1°
2047-04-19 Fri	63	—	unknown	02:15–04:55 (good, 2.67 h)	87.2° 08:30	7.07	23%	54.4°
2047-04-20 Sat	67	—	unknown	02:10–04:50 (good, 2.67 h)	87.2° 08:25	7.01	16%	53.5°
2047-04-21 Sun	70	—	unknown	02:05–04:50 (good, 2.75 h)	87.2° 08:20	6.95	10%	54.5°
2047-04-22 Mon	71	—	unknown	02:00–04:50 (good, 2.83 h)	87.2° 08:15	6.89	5%	57.1°
2047-04-23 Tue	71	—	unknown	02:00–04:45 (good, 2.75 h)	87.2° 08:15	6.83	2%	61.2°
2047-04-24 Wed	73	—	unknown	01:55–04:45 (good, 2.83 h)	87.2° 08:10	6.78	0%	66.5°
2047-04-25 Thu	75	—	unknown	01:50–04:45 (good, 2.92 h)	87.2° 08:05	6.72	1%	72.5°
2047-04-26 Fri	75	—	unknown	01:45–04:40 (good, 2.92 h)	87.2° 08:00	6.66	3%	79.2°
2047-04-27 Sat	77	—	unknown	01:40–04:40 (good, 3.0 h)	87.2° 07:55	6.6	7%	86.2°
2047-04-28 Sun	76	—	unknown	01:40–04:35 (good, 2.92 h)	87.2° 07:55	6.54	12%	93.4°
2047-04-29 Mon	78	—	unknown	01:35–04:35 (good, 3.0 h)	87.2° 07:50	6.48	19%	100.6°
2047-04-30 Tue	80	—	unknown	01:30–04:35 (good, 3.08 h)	87.2° 07:45	6.43	28%	107.5°
2047-05-01 Wed	79	—	unknown	01:30–04:30 (good, 3.0 h)	87.2° 07:40	6.37	37%	114.0°
2047-05-02 Thu	80	—	unknown	01:25–04:30 (good, 3.08 h)	87.2° 07:40	6.31	48%	119.7°
2047-05-03 Fri	81	—	unknown	01:25–04:30 (good, 3.08 h)	87.2° 07:35	6.25	58%	124.0°
2047-05-04 Sat	80	—	unknown	01:25–04:25 (good, 3.0 h)	87.2° 07:30	6.19	69%	126.4°
2047-05-05 Sun	81	—	unknown	01:20–04:25 (good, 3.08 h)	87.2° 07:25	6.14	79%	126.3°
2047-05-06 Mon	79	—	unknown	01:20–04:20 (good, 3.0 h)	87.2° 07:20	6.08	88%	123.5°
2047-05-07 Tue	72	—	unknown	01:15–04:20 (good, 3.08 h)	87.2° 07:20	6.02	95%	118.4°
2047-05-08 Wed	66	—	unknown	01:20–04:20 (good, 3.0 h)	87.2° 07:15	5.97	99%	111.3°
2047-05-09 Thu	60	—	unknown	01:20–04:15 (good, 2.92 h)	87.2° 07:10	5.91	100%	103.1°
2047-05-10 Fri	55	—	unknown	01:20–04:15 (good, 2.92 h)	87.2° 07:05	5.85	98%	94.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-04-11&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.