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: 08-21 (100), 08-22 (100), 08-23 (100), 08-24 (100), 08-25 (100) — by astronomy; check the weather when the night is within four days.

2033-08-21astronomy score per night — click a bar for that night2033-09-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-08-21 Sun	100	—	unknown	21:55–04:55 (good, 7.0 h)	87.3° 00:20	7.0	9%	117.2°
2033-08-22 Mon	100	—	unknown	21:55–05:00 (good, 7.08 h)	87.3° 00:15	7.06	4%	121.7°
2033-08-23 Tue	100	—	unknown	21:55–05:00 (good, 7.08 h)	87.3° 00:10	7.12	1%	124.6°
2033-08-24 Wed	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.3° 00:05	7.18	0%	125.7°
2033-08-25 Thu	100	—	unknown	21:50–05:05 (good, 7.25 h)	87.3° 00:05	7.23	1%	124.9°
2033-08-26 Fri	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.3° 00:00	7.29	4%	122.4°
2033-08-27 Sat	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.3° 23:55	7.35	8%	118.5°
2033-08-28 Sun	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.3° 23:50	7.4	14%	113.5°
2033-08-29 Mon	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.3° 23:50	7.46	21%	107.6°
2033-08-30 Tue	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.3° 23:45	7.52	30%	101.2°
2033-08-31 Wed	100	—	unknown	21:35–05:10 (good, 7.58 h)	87.3° 23:40	7.57	39%	94.3°
2033-09-01 Thu	100	—	unknown	21:35–05:10 (good, 7.58 h)	87.3° 23:35	7.63	48%	87.2°
2033-09-02 Fri	100	—	unknown	21:35–05:15 (good, 7.67 h)	87.3° 23:30	7.68	58%	80.0°
2033-09-03 Sat	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.3° 23:30	7.74	68%	73.0°
2033-09-04 Sun	98	—	unknown	21:30–05:15 (good, 7.75 h)	87.3° 23:25	7.79	78%	66.4°
2033-09-05 Mon	90	—	unknown	21:25–05:20 (good, 7.92 h)	87.3° 23:20	7.85	86%	60.7°
2033-09-06 Tue	82	—	unknown	04:40–05:20 (good, 0.67 h)	87.3° 23:15	7.9	93%	56.4°
2033-09-07 Wed	56	—	unknown	21:25–05:20 (marginal, 7.92 h)	87.3° 23:10	7.96	98%	54.4°
2033-09-08 Thu	58	—	unknown	21:20–05:20 (marginal, 8.0 h)	87.3° 23:10	8.01	100%	55.0°
2033-09-09 Fri	62	—	unknown	21:20–21:50 (good, 0.5 h)	87.3° 23:05	8.07	99%	58.4°
2033-09-10 Sat	70	—	unknown	21:15–23:25 (good, 2.17 h)	87.3° 23:00	8.12	95%	63.9°
2033-09-11 Sun	77	—	unknown	21:15–01:55 (good, 4.67 h)	87.3° 22:55	8.18	88%	71.0°
2033-09-12 Mon	100	—	unknown	21:15–03:15 (good, 6.0 h)	87.3° 22:55	8.23	80%	79.0°
2033-09-13 Tue	100	—	unknown	21:10–04:30 (good, 7.33 h)	87.3° 22:50	8.28	70%	87.2°
2033-09-14 Wed	100	—	unknown	21:10–04:45 (good, 7.58 h)	87.3° 22:45	8.34	59%	95.4°
2033-09-15 Thu	100	—	unknown	21:05–04:45 (good, 7.67 h)	87.3° 22:40	8.39	48%	103.1°
2033-09-16 Fri	100	—	unknown	21:05–04:50 (good, 7.75 h)	87.3° 22:35	8.44	37%	110.0°
2033-09-17 Sat	100	—	unknown	21:05–04:50 (good, 7.75 h)	87.3° 22:35	8.49	28%	116.0°
2033-09-18 Sun	100	—	unknown	21:00–04:45 (good, 7.75 h)	87.3° 22:30	8.54	19%	120.8°
2033-09-19 Mon	100	—	unknown	21:00–04:45 (good, 7.75 h)	87.3° 22:25	8.6	12%	124.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-08-21&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.