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: 04-12 (62), 04-11 (61), 04-14 (61), 04-09 (60), 04-13 (60) — by astronomy; check the weather when the night is within four days.

2038-03-19astronomy score per night — click a bar for that night2038-04-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-03-19 Fri	33	—	unknown	03:30–04:55 (good, 1.42 h)	87.3° 09:30	8.77	98%	118.3°
2038-03-20 Sat	32	—	unknown	03:30–04:50 (good, 1.33 h)	87.3° 09:25	8.72	100%	116.0°
2038-03-21 Sun	31	—	unknown	03:30–04:50 (good, 1.33 h)	87.3° 09:20	8.67	99%	111.7°
2038-03-22 Mon	29	—	unknown	03:30–04:50 (good, 1.33 h)	87.3° 09:20	8.61	95%	106.1°
2038-03-23 Tue	28	—	unknown	03:25–04:45 (good, 1.33 h)	87.3° 09:15	8.56	88%	99.6°
2038-03-24 Wed	29	—	unknown	03:20–04:45 (good, 1.42 h)	87.3° 09:10	8.51	79%	92.7°
2038-03-25 Thu	30	—	unknown	03:15–04:45 (good, 1.5 h)	87.3° 09:05	8.46	69%	85.9°
2038-03-26 Fri	32	—	unknown	03:05–04:40 (good, 1.58 h)	87.3° 09:00	8.4	59%	79.5°
2038-03-27 Sat	35	—	unknown	04:00–05:40 (good, 1.67 h)	87.3° 10:00	8.35	48%	73.7°
2038-03-28 Sun	39	—	unknown	03:40–05:35 (good, 1.92 h)	87.3° 09:55	8.3	38%	68.9°
2038-03-29 Mon	46	—	unknown	03:35–05:35 (good, 2.0 h)	87.3° 09:50	8.24	28%	65.1°
2038-03-30 Tue	51	—	unknown	03:30–05:35 (good, 2.08 h)	87.3° 09:45	8.19	20%	62.6°
2038-03-31 Wed	51	—	unknown	03:25–05:30 (good, 2.08 h)	87.3° 09:40	8.13	12%	61.4°
2038-04-01 Thu	52	—	unknown	03:25–05:30 (good, 2.08 h)	87.3° 09:40	8.08	7%	61.6°
2038-04-02 Fri	52	—	unknown	03:20–05:25 (good, 2.08 h)	87.3° 09:35	8.02	3%	63.2°
2038-04-03 Sat	54	—	unknown	03:15–05:25 (good, 2.17 h)	87.3° 09:30	7.97	1%	65.9°
2038-04-04 Sun	56	—	unknown	03:10–05:25 (good, 2.25 h)	87.3° 09:25	7.91	0%	69.7°
2038-04-05 Mon	55	—	unknown	03:10–05:20 (good, 2.17 h)	87.3° 09:25	7.86	2%	74.2°
2038-04-06 Tue	57	—	unknown	03:05–05:20 (good, 2.25 h)	87.3° 09:20	7.8	5%	79.3°
2038-04-07 Wed	58	—	unknown	03:00–05:20 (good, 2.33 h)	87.3° 09:15	7.74	9%	84.8°
2038-04-08 Thu	58	—	unknown	02:55–05:15 (good, 2.33 h)	87.3° 09:10	7.69	16%	90.5°
2038-04-09 Fri	60	—	unknown	02:50–05:15 (good, 2.42 h)	87.3° 09:05	7.63	23%	96.3°
2038-04-10 Sat	59	—	unknown	02:50–05:10 (good, 2.33 h)	87.3° 09:05	7.57	32%	101.9°
2038-04-11 Sun	61	—	unknown	02:45–05:10 (good, 2.42 h)	87.3° 09:00	7.52	42%	107.2°
2038-04-12 Mon	62	—	unknown	02:45–05:10 (good, 2.42 h)	87.3° 08:55	7.46	52%	111.8°
2038-04-13 Tue	60	—	unknown	02:45–05:05 (good, 2.33 h)	87.3° 08:50	7.4	62%	115.5°
2038-04-14 Wed	61	—	unknown	02:40–05:05 (good, 2.42 h)	87.3° 08:45	7.35	73%	117.9°
2038-04-15 Thu	55	—	unknown	02:40–05:00 (good, 2.33 h)	87.3° 08:45	7.29	82%	118.5°
2038-04-16 Fri	53	—	unknown	02:40–05:00 (good, 2.33 h)	87.3° 08:40	7.23	90%	117.2°
2038-04-17 Sat	51	—	unknown	02:40–05:00 (good, 2.33 h)	87.3° 08:35	7.17	96%	113.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-03-19&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.