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: 10-20 (100), 11-01 (100), 11-02 (100), 11-03 (100), 11-04 (100) — by astronomy; check the weather when the night is within four days.

2037-10-20astronomy score per night — click a bar for that night2037-11-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-10-20 Tue	100	—	unknown	00:45–06:10 (good, 5.42 h)	72.5° 03:10	10.05	90%	68.2°
2037-10-21 Wed	96	—	unknown	03:30–06:10 (good, 2.67 h)	72.5° 03:05	10.09	95%	56.5°
2037-10-22 Thu	58	—	unknown	22:05–06:10 (marginal, 8.08 h)	72.5° 03:05	10.13	98%	44.8°
2037-10-23 Fri	36	—	unknown	01:10–06:15 (marginal, 5.08 h)	72.5° 03:00	10.17	100%	33.2°
2037-10-24 Sat	27	—	unknown	03:45–05:15 (marginal, 2.5 h)	72.5° 02:55	10.21	99%	21.7°
2037-10-25 Sun	24	—	unknown	20:55–23:20 (marginal, 2.42 h)	72.5° 01:50	10.25	97%	11.4°
2037-10-26 Mon	30	—	unknown	20:35–01:15 (marginal, 4.67 h)	72.5° 01:45	10.29	93%	9.2°
2037-10-27 Tue	40	—	unknown	20:20–05:15 (marginal, 8.92 h)	72.5° 01:45	10.33	87%	18.7°
2037-10-28 Wed	56	—	unknown	20:05–05:20 (marginal, 9.25 h)	72.5° 01:40	10.37	79%	30.6°
2037-10-29 Thu	83	—	unknown	20:30–00:55 (good, 4.42 h)	72.5° 01:35	10.4	70%	43.2°
2037-10-30 Fri	90	—	unknown	20:25–04:35 (good, 8.17 h)	72.5° 01:30	10.44	60%	56.2°
2037-10-31 Sat	98	—	unknown	20:20–05:20 (good, 9.0 h)	72.5° 01:25	10.48	50%	69.5°
2037-11-01 Sun	100	—	unknown	20:15–05:25 (good, 9.17 h)	72.5° 01:25	10.51	38%	83.2°
2037-11-02 Mon	100	—	unknown	20:15–05:25 (good, 9.17 h)	72.5° 01:20	10.55	28%	97.3°
2037-11-03 Tue	100	—	unknown	20:10–05:25 (good, 9.25 h)	72.5° 01:15	10.58	18%	111.7°
2037-11-04 Wed	100	—	unknown	20:05–05:25 (good, 9.33 h)	72.5° 01:10	10.62	10%	126.3°
2037-11-05 Thu	100	—	unknown	20:00–05:25 (good, 9.42 h)	72.5° 01:10	10.65	4%	140.9°
2037-11-06 Fri	100	—	unknown	20:00–05:30 (good, 9.5 h)	72.5° 01:05	10.69	1%	155.3°
2037-11-07 Sat	100	—	unknown	19:55–05:30 (good, 9.58 h)	72.5° 01:00	10.72	0%	168.2°
2037-11-08 Sun	100	—	unknown	19:50–05:30 (good, 9.67 h)	72.5° 00:55	10.75	3%	170.0°
2037-11-09 Mon	100	—	unknown	19:45–05:30 (good, 9.75 h)	72.5° 00:50	10.79	8%	158.4°
2037-11-10 Tue	100	—	unknown	19:40–05:30 (good, 9.83 h)	72.5° 00:50	10.82	15%	145.3°
2037-11-11 Wed	100	—	unknown	19:40–05:35 (good, 9.92 h)	72.5° 00:45	10.85	23%	132.3°
2037-11-12 Thu	100	—	unknown	19:35–05:35 (good, 10.0 h)	72.5° 00:40	10.88	32%	119.6°
2037-11-13 Fri	100	—	unknown	19:35–05:35 (good, 10.0 h)	72.5° 00:35	10.91	42%	107.2°
2037-11-14 Sat	100	—	unknown	19:40–05:35 (good, 9.92 h)	72.5° 00:30	10.94	52%	95.2°
2037-11-15 Sun	100	—	unknown	19:45–05:35 (good, 9.83 h)	72.5° 00:30	10.97	61%	83.3°
2037-11-16 Mon	100	—	unknown	20:20–05:35 (good, 9.25 h)	72.5° 00:25	11.0	70%	71.6°
2037-11-17 Tue	99	—	unknown	21:55–05:30 (good, 7.58 h)	72.5° 00:20	11.02	78%	59.9°
2037-11-18 Wed	92	—	unknown	01:15–05:25 (good, 4.17 h)	72.5° 00:15	11.05	86%	48.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-10-20&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.