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: 05-01 (70), 04-13 (63), 04-14 (63), 04-15 (63), 04-16 (63) — by astronomy; check the weather when the night is within four days.

2035-04-02astronomy score per night — click a bar for that night2035-05-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-04-02 Mon	45	—	unknown	03:20–05:30 (good, 2.17 h)	87.3° 09:35	8.04	31%	60.5°
2035-04-03 Tue	50	—	unknown	03:15–05:25 (good, 2.17 h)	87.3° 09:30	7.98	22%	57.7°
2035-04-04 Wed	54	—	unknown	03:15–05:25 (good, 2.17 h)	87.3° 09:30	7.93	14%	56.6°
2035-04-05 Thu	55	—	unknown	03:10–05:20 (good, 2.17 h)	87.3° 09:25	7.87	8%	57.4°
2035-04-06 Fri	56	—	unknown	03:05–05:20 (good, 2.25 h)	87.3° 09:20	7.82	3%	60.3°
2035-04-07 Sat	58	—	unknown	03:00–05:20 (good, 2.33 h)	87.3° 09:15	7.76	0%	64.9°
2035-04-08 Sun	58	—	unknown	02:55–05:15 (good, 2.33 h)	87.3° 09:10	7.7	0%	71.1°
2035-04-09 Mon	59	—	unknown	02:55–05:15 (good, 2.33 h)	87.3° 09:10	7.65	3%	78.3°
2035-04-10 Tue	59	—	unknown	02:50–05:10 (good, 2.33 h)	87.3° 09:05	7.59	8%	86.2°
2035-04-11 Wed	61	—	unknown	02:45–05:10 (good, 2.42 h)	87.3° 09:00	7.53	16%	94.2°
2035-04-12 Thu	62	—	unknown	02:40–05:10 (good, 2.5 h)	87.3° 08:55	7.48	26%	102.0°
2035-04-13 Fri	63	—	unknown	02:35–05:05 (good, 2.5 h)	87.3° 08:50	7.42	37%	109.1°
2035-04-14 Sat	63	—	unknown	02:35–05:05 (good, 2.5 h)	87.3° 08:50	7.36	48%	115.2°
2035-04-15 Sun	63	—	unknown	02:35–05:00 (good, 2.42 h)	87.3° 08:45	7.3	59%	119.8°
2035-04-16 Mon	63	—	unknown	02:35–05:00 (good, 2.42 h)	87.3° 08:40	7.25	70%	122.5°
2035-04-17 Tue	63	—	unknown	02:30–05:00 (good, 2.5 h)	87.3° 08:35	7.19	79%	123.3°
2035-04-18 Wed	57	—	unknown	02:30–04:55 (good, 2.42 h)	87.3° 08:35	7.13	87%	122.1°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-04-02&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.