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.

2046-08-17astronomy score per night — click a bar for that night2046-09-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-08-17 Fri	59	—	unknown	22:05–22:15 (good, 0.17 h)	87.2° 00:35	6.77	98%	54.4°
2046-08-18 Sat	63	—	unknown	22:05–22:50 (good, 0.75 h)	87.2° 00:30	6.82	95%	54.4°
2046-08-19 Sun	68	—	unknown	22:00–23:45 (good, 1.75 h)	87.2° 00:30	6.88	90%	56.2°
2046-08-20 Mon	73	—	unknown	22:00–01:10 (good, 3.17 h)	87.2° 00:25	6.94	84%	59.5°
2046-08-21 Tue	100	—	unknown	21:55–03:25 (good, 5.5 h)	87.3° 00:20	7.0	76%	64.1°
2046-08-22 Wed	100	—	unknown	21:55–04:35 (good, 6.67 h)	87.2° 00:15	7.05	68%	69.8°
2046-08-23 Thu	100	—	unknown	21:55–05:00 (good, 7.08 h)	87.2° 00:10	7.11	58%	76.1°
2046-08-24 Fri	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.2° 00:10	7.17	48%	83.1°
2046-08-25 Sat	100	—	unknown	21:50–05:05 (good, 7.25 h)	87.2° 00:05	7.23	38%	90.5°
2046-08-26 Sun	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.3° 00:00	7.28	28%	98.1°
2046-08-27 Mon	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.2° 23:55	7.34	19%	105.6°
2046-08-28 Tue	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.2° 23:55	7.4	11%	112.7°
2046-08-29 Wed	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:50	7.45	5%	118.9°
2046-08-30 Thu	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.3° 23:45	7.51	1%	123.5°
2046-08-31 Fri	100	—	unknown	21:35–05:10 (good, 7.58 h)	87.2° 23:40	7.56	0%	125.7°
2046-09-01 Sat	100	—	unknown	21:35–05:10 (good, 7.58 h)	87.2° 23:35	7.62	2%	125.0°
2046-09-02 Sun	100	—	unknown	21:35–05:15 (good, 7.67 h)	87.2° 23:35	7.68	7%	121.7°
2046-09-03 Mon	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.2° 23:30	7.73	15%	116.2°
2046-09-04 Tue	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.3° 23:25	7.79	24%	109.4°
2046-09-05 Wed	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.2° 23:20	7.84	34%	101.7°
2046-09-06 Thu	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.2° 23:15	7.9	45%	93.9°
2046-09-07 Fri	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.2° 23:15	7.95	56%	86.0°
2046-09-08 Sat	100	—	unknown	21:20–05:20 (good, 8.0 h)	87.2° 23:10	8.01	66%	78.6°
2046-09-09 Sun	100	—	unknown	21:20–05:25 (good, 8.08 h)	87.3° 23:05	8.06	75%	71.7°
2046-09-10 Mon	92	—	unknown	21:15–05:20 (good, 8.08 h)	87.2° 23:00	8.11	83%	65.6°
2046-09-11 Tue	84	—	unknown	21:15–05:20 (good, 8.08 h)	87.2° 23:00	8.17	90%	60.6°
2046-09-12 Wed	67	—	unknown	05:00–05:15 (good, 0.25 h)	87.2° 22:55	8.22	95%	56.8°
2046-09-13 Thu	56	—	unknown	21:10–05:30 (marginal, 8.33 h)	87.3° 22:50	8.27	98%	54.7°
2046-09-14 Fri	57	—	unknown	21:10–05:20 (marginal, 8.17 h)	87.2° 22:45	8.33	100%	54.3°
2046-09-15 Sat	59	—	unknown	21:05–05:10 (marginal, 8.08 h)	87.2° 22:40	8.38	100%	55.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-08-17&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.