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: 10-30 (100), 10-31 (100), 11-01 (100), 11-02 (100), 11-03 (100) — by astronomy; check the weather when the night is within four days.

2029-10-20astronomy score per night — click a bar for that night2029-11-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-10-20 Sat	58	—	unknown	22:20–06:10 (marginal, 7.83 h)	72.5° 03:10	10.05	98%	47.9°
2029-10-21 Sun	36	—	unknown	01:35–06:10 (marginal, 4.58 h)	72.5° 03:05	10.09	100%	36.0°
2029-10-22 Mon	24	—	unknown	04:00–06:10 (marginal, 2.17 h)	72.5° 03:00	10.13	100%	24.2°
2029-10-23 Tue	22	—	unknown	04:40–06:15 (marginal, 1.58 h)	72.5° 03:00	10.17	98%	12.4°
2029-10-24 Wed	24	—	unknown	21:55–01:00 (marginal, 3.08 h)	72.5° 02:55	10.21	94%	1.8°
2029-10-25 Thu	33	—	unknown	21:35–06:15 (marginal, 8.67 h)	72.5° 02:50	10.25	89%	11.6°
2029-10-26 Fri	45	—	unknown	21:20–06:15 (marginal, 8.92 h)	72.5° 02:45	10.29	83%	23.5°
2029-10-27 Sat	68	—	unknown	21:35–21:50 (good, 0.25 h)	72.5° 02:45	10.32	75%	35.7°
2029-10-28 Sun	86	—	unknown	20:35–03:00 (good, 6.42 h)	72.5° 01:40	10.36	66%	48.0°
2029-10-29 Mon	94	—	unknown	20:30–05:20 (good, 8.83 h)	72.5° 01:35	10.4	56%	60.7°
2029-10-30 Tue	100	—	unknown	20:25–05:20 (good, 8.92 h)	72.5° 01:30	10.44	45%	73.7°
2029-10-31 Wed	100	—	unknown	20:20–05:20 (good, 9.0 h)	72.5° 01:25	10.48	35%	87.1°
2029-11-01 Thu	100	—	unknown	20:15–05:25 (good, 9.17 h)	72.5° 01:25	10.51	25%	100.9°
2029-11-02 Fri	100	—	unknown	20:15–05:25 (good, 9.17 h)	72.5° 01:20	10.55	15%	115.3°
2029-11-03 Sat	100	—	unknown	20:10–05:25 (good, 9.25 h)	72.5° 01:15	10.58	8%	130.0°
2029-11-04 Sun	100	—	unknown	20:05–05:25 (good, 9.33 h)	72.5° 01:10	10.62	3%	145.0°
2029-11-05 Mon	100	—	unknown	20:00–05:25 (good, 9.42 h)	72.5° 01:05	10.65	0%	160.3°
2029-11-06 Tue	100	—	unknown	20:00–05:30 (good, 9.5 h)	72.5° 01:05	10.69	1%	175.3°
2029-11-07 Wed	100	—	unknown	19:55–05:30 (good, 9.58 h)	72.5° 01:00	10.72	4%	169.1°
2029-11-08 Thu	100	—	unknown	19:50–05:30 (good, 9.67 h)	72.5° 00:55	10.75	11%	154.4°
2029-11-09 Fri	100	—	unknown	19:45–05:30 (good, 9.75 h)	72.5° 00:50	10.79	19%	140.1°
2029-11-10 Sat	100	—	unknown	19:45–05:30 (good, 9.75 h)	72.5° 00:50	10.82	28%	126.2°
2029-11-11 Sun	100	—	unknown	19:45–05:35 (good, 9.83 h)	72.5° 00:45	10.85	39%	112.8°
2029-11-12 Mon	100	—	unknown	19:45–05:35 (good, 9.83 h)	72.5° 00:40	10.88	49%	99.8°
2029-11-13 Tue	100	—	unknown	19:50–05:35 (good, 9.75 h)	72.5° 00:35	10.91	59%	87.2°
2029-11-14 Wed	100	—	unknown	20:20–05:35 (good, 9.25 h)	72.5° 00:30	10.94	68%	74.9°
2029-11-15 Thu	99	—	unknown	21:55–05:35 (good, 7.67 h)	72.5° 00:30	10.97	77%	62.8°
2029-11-16 Fri	91	—	unknown	01:05–05:35 (good, 4.5 h)	72.5° 00:25	11.0	84%	50.9°
2029-11-17 Sat	83	—	unknown	04:35–05:30 (good, 0.92 h)	72.5° 00:20	11.02	91%	39.0°
2029-11-18 Sun	48	—	unknown	00:05–05:40 (marginal, 5.58 h)	72.5° 00:15	11.05	95%	27.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-10-20&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.