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: 09-01 (100), 09-02 (100), 09-03 (100), 09-12 (100), 09-13 (100) — by astronomy; check the weather when the night is within four days.

2033-09-01astronomy score per night — click a bar for that night2033-09-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2033-09-20 Tue	100	—	unknown	21:00–04:40 (good, 7.67 h)	87.3° 22:20	8.65	6%	125.6°
2033-09-21 Wed	100	—	unknown	20:55–04:35 (good, 7.67 h)	87.3° 22:15	8.7	2%	125.3°
2033-09-22 Thu	100	—	unknown	20:55–04:35 (good, 7.67 h)	87.3° 22:15	8.75	0%	123.2°
2033-09-23 Fri	100	—	unknown	20:50–04:30 (good, 7.67 h)	87.3° 22:10	8.8	0%	119.7°
2033-09-24 Sat	100	—	unknown	20:50–04:25 (good, 7.58 h)	87.3° 22:05	8.85	2%	114.9°
2033-09-25 Sun	100	—	unknown	20:50–04:20 (good, 7.5 h)	87.3° 22:00	8.9	5%	109.2°
2033-09-26 Mon	100	—	unknown	20:45–04:15 (good, 7.5 h)	87.3° 22:00	8.95	10%	102.9°
2033-09-27 Tue	100	—	unknown	20:45–04:15 (good, 7.5 h)	87.3° 21:55	9.0	16%	96.2°
2033-09-28 Wed	100	—	unknown	20:45–04:10 (good, 7.42 h)	87.3° 21:50	9.05	24%	89.2°
2033-09-29 Thu	100	—	unknown	20:40–04:05 (good, 7.42 h)	87.3° 21:45	9.1	32%	82.1°
2033-09-30 Fri	100	—	unknown	20:40–04:00 (good, 7.33 h)	87.3° 21:40	9.15	42%	75.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-09-01&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.