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: 05-14 (94), 05-13 (93), 05-11 (92), 05-12 (92), 05-15 (92) — by astronomy; check the weather when the night is within four days.

2035-04-19astronomy score per night — click a bar for that night2035-05-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-04-19 Thu	55	—	unknown	02:30–04:55 (good, 2.42 h)	87.3° 08:30	7.07	93%	119.1°
2035-04-20 Fri	53	—	unknown	02:30–04:55 (good, 2.42 h)	87.3° 08:25	7.01	97%	114.7°
2035-04-21 Sat	49	—	unknown	02:30–04:50 (good, 2.33 h)	87.3° 08:20	6.96	100%	109.3°
2035-04-22 Sun	45	—	unknown	02:30–04:50 (good, 2.33 h)	87.3° 08:15	6.9	100%	103.2°
2035-04-23 Mon	42	—	unknown	02:30–04:45 (good, 2.25 h)	87.3° 08:15	6.84	98%	96.8°
2035-04-24 Tue	40	—	unknown	02:45–04:45 (good, 2.0 h)	87.3° 08:10	6.78	94%	90.2°
2035-04-25 Wed	39	—	unknown	02:50–04:45 (good, 1.92 h)	87.3° 08:05	6.72	90%	83.7°
2035-04-26 Thu	39	—	unknown	02:35–04:40 (good, 2.08 h)	87.3° 08:00	6.67	83%	77.4°
2035-04-27 Fri	41	—	unknown	02:15–04:40 (good, 2.42 h)	87.3° 07:55	6.61	75%	71.6°
2035-04-28 Sat	44	—	unknown	02:05–04:35 (good, 2.5 h)	87.3° 07:55	6.55	67%	66.3°
2035-04-29 Sun	55	—	unknown	01:35–04:35 (good, 3.0 h)	87.3° 07:50	6.49	57%	61.9°
2035-04-30 Mon	63	—	unknown	01:30–04:35 (good, 3.08 h)	87.3° 07:45	6.43	48%	58.7°
2035-05-01 Tue	70	—	unknown	01:25–04:30 (good, 3.08 h)	87.3° 07:40	6.37	38%	57.0°
2035-05-02 Wed	76	—	unknown	01:25–04:30 (good, 3.08 h)	87.3° 07:40	6.32	28%	57.0°
2035-05-03 Thu	83	—	unknown	01:20–04:30 (good, 3.17 h)	87.3° 07:35	6.26	19%	59.0°
2035-05-04 Fri	83	—	unknown	01:15–04:25 (good, 3.17 h)	87.3° 07:30	6.2	11%	62.8°
2035-05-05 Sat	85	—	unknown	01:10–04:25 (good, 3.25 h)	87.3° 07:25	6.14	5%	68.3°
2035-05-06 Sun	87	—	unknown	01:05–04:25 (good, 3.33 h)	87.3° 07:20	6.09	1%	75.2°
2035-05-07 Mon	87	—	unknown	01:05–04:20 (good, 3.25 h)	87.3° 07:20	6.03	0%	82.9°
2035-05-08 Tue	88	—	unknown	01:00–04:20 (good, 3.33 h)	87.3° 07:15	5.97	2%	91.1°
2035-05-09 Wed	89	—	unknown	00:55–04:15 (good, 3.33 h)	87.3° 07:10	5.92	7%	99.2°
2035-05-10 Thu	91	—	unknown	00:50–04:15 (good, 3.42 h)	87.3° 07:05	5.86	14%	106.8°
2035-05-11 Fri	92	—	unknown	00:45–04:15 (good, 3.5 h)	87.3° 07:00	5.81	23%	113.4°
2035-05-12 Sat	92	—	unknown	00:45–04:10 (good, 3.42 h)	87.3° 07:00	5.75	33%	118.5°
2035-05-13 Sun	93	—	unknown	00:45–04:10 (good, 3.42 h)	87.3° 06:55	5.7	44%	121.8°
2035-05-14 Mon	94	—	unknown	00:40–04:10 (good, 3.5 h)	87.3° 06:50	5.64	55%	123.1°
2035-05-15 Tue	92	—	unknown	00:40–04:05 (good, 3.42 h)	87.3° 06:45	5.59	66%	122.4°
2035-05-16 Wed	92	—	unknown	00:40–04:05 (good, 3.42 h)	87.3° 06:40	5.53	75%	119.8°
2035-05-17 Thu	83	—	unknown	00:40–04:05 (good, 3.42 h)	87.3° 06:40	5.48	83%	115.8°
2035-05-18 Fri	78	—	unknown	00:40–04:05 (good, 3.42 h)	87.3° 06:35	5.43	90%	110.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-04-19&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.