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 Seven Sisters: 10-16 (100), 10-17 (100), 10-18 (100), 10-19 (100), 10-20 (100) — by astronomy; check the weather when the night is within four days.

2045-10-16astronomy score per night — click a bar for that night2045-11-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-10-16 Mon	100	—	unknown	22:25–06:05 (good, 7.67 h)	72.6° 03:25	9.88	42%	135.5°
2045-10-17 Tue	100	—	unknown	22:20–06:05 (good, 7.75 h)	72.6° 03:25	9.92	51%	123.4°
2045-10-18 Wed	100	—	unknown	22:20–06:10 (good, 7.83 h)	72.6° 03:20	9.97	61%	111.5°
2045-10-19 Thu	100	—	unknown	22:25–06:10 (good, 7.75 h)	72.6° 03:15	10.01	70%	99.7°
2045-10-20 Fri	100	—	unknown	22:30–06:10 (good, 7.67 h)	72.6° 03:10	10.05	78%	87.8°
2045-10-21 Sat	100	—	unknown	23:40–06:10 (good, 6.5 h)	72.6° 03:05	10.09	85%	75.9°
2045-10-22 Sun	99	—	unknown	01:40–06:10 (good, 4.5 h)	72.6° 03:05	10.13	91%	63.9°
2045-10-23 Mon	92	—	unknown	04:35–06:15 (good, 1.67 h)	72.6° 03:00	10.17	96%	51.6°
2045-10-24 Tue	44	—	unknown	23:55–06:15 (marginal, 6.33 h)	72.6° 02:55	10.21	99%	39.2°
2045-10-25 Wed	27	—	unknown	03:40–06:15 (marginal, 2.58 h)	72.6° 02:50	10.25	100%	26.5°
2045-10-26 Thu	22	—	unknown	04:35–06:15 (marginal, 1.67 h)	72.6° 02:45	10.29	99%	13.6°
2045-10-27 Fri	22	—	unknown	21:50–23:50 (marginal, 2.0 h)	72.6° 02:45	10.33	95%	0.9°
2045-10-28 Sat	32	—	unknown	21:30–02:45 (marginal, 5.25 h)	72.6° 02:40	10.37	90%	12.9°
2045-10-29 Sun	46	—	unknown	20:10–05:20 (marginal, 9.17 h)	72.6° 01:35	10.41	82%	26.4°
2045-10-30 Mon	69	—	unknown	22:10–23:45 (good, 1.58 h)	72.6° 01:30	10.44	73%	40.1°
2045-10-31 Tue	88	—	unknown	20:20–04:00 (good, 7.67 h)	72.6° 01:30	10.48	63%	53.9°
2045-11-01 Wed	98	—	unknown	20:20–05:25 (good, 9.08 h)	72.6° 01:25	10.52	52%	67.9°
2045-11-02 Thu	100	—	unknown	20:15–05:25 (good, 9.17 h)	72.6° 01:20	10.55	41%	82.0°
2045-11-03 Fri	100	—	unknown	20:10–05:25 (good, 9.25 h)	72.6° 01:15	10.59	30%	96.3°
2045-11-04 Sat	100	—	unknown	20:05–05:25 (good, 9.33 h)	72.6° 01:10	10.62	20%	110.6°
2045-11-05 Sun	100	—	unknown	20:00–05:25 (good, 9.42 h)	72.6° 01:10	10.66	11%	124.9°
2045-11-06 Mon	100	—	unknown	20:00–05:30 (good, 9.5 h)	72.6° 01:05	10.69	5%	139.2°
2045-11-07 Tue	100	—	unknown	19:55–05:30 (good, 9.58 h)	72.6° 01:00	10.72	1%	153.3°
2045-11-08 Wed	100	—	unknown	19:50–05:30 (good, 9.67 h)	72.6° 00:55	10.76	0%	167.3°
2045-11-09 Thu	100	—	unknown	19:45–05:30 (good, 9.75 h)	72.6° 00:50	10.79	1%	178.7°
2045-11-10 Fri	100	—	unknown	19:40–05:30 (good, 9.83 h)	72.6° 00:50	10.82	5%	165.7°
2045-11-11 Sat	100	—	unknown	19:40–05:35 (good, 9.92 h)	72.6° 00:45	10.85	10%	152.7°
2045-11-12 Sun	100	—	unknown	19:35–05:35 (good, 10.0 h)	72.6° 00:40	10.88	17%	140.0°
2045-11-13 Mon	100	—	unknown	19:30–05:35 (good, 10.08 h)	72.6° 00:35	10.91	25%	127.7°
2045-11-14 Tue	100	—	unknown	19:30–05:35 (good, 10.08 h)	72.6° 00:30	10.94	34%	115.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-10-16&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.