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: 10-10 (100), 10-11 (100), 10-12 (100), 10-13 (100), 10-14 (100) — by astronomy; check the weather when the night is within four days.

2026-10-10astronomy score per night — click a bar for that night2026-11-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2026-10-10 Sat	100	99	99	22:45–06:00 (good, 7.25 h)	72.5° 03:50	9.6	0%	141.1°
2026-10-11 Sun	100	0	0	—	72.5° 03:45	9.64	2%	153.9°
2026-10-12 Mon	100	0	0	—	72.5° 03:45	9.69	6%	166.4°
2026-10-13 Tue	100	0	0	03:00–06:00 (good, 3.0 h)	72.5° 03:40	9.73	11%	178.4°
2026-10-14 Wed	100	—	unknown	22:30–06:05 (good, 7.58 h)	72.5° 03:35	9.78	17%	169.1°
2026-10-15 Thu	100	—	unknown	22:25–06:05 (good, 7.67 h)	72.5° 03:30	9.82	25%	157.2°
2026-10-16 Fri	100	—	unknown	22:20–06:05 (good, 7.75 h)	72.5° 03:25	9.86	34%	145.3°
2026-10-17 Sat	100	—	unknown	22:20–06:05 (good, 7.75 h)	72.5° 03:25	9.91	43%	133.5°
2026-10-18 Sun	100	—	unknown	22:20–06:05 (good, 7.75 h)	72.5° 03:20	9.95	52%	121.6°
2026-10-19 Mon	100	—	unknown	22:20–06:10 (good, 7.83 h)	72.5° 03:15	9.99	62%	109.6°
2026-10-20 Tue	100	—	unknown	22:20–06:10 (good, 7.83 h)	72.5° 03:10	10.03	71%	97.3°
2026-10-21 Wed	100	—	unknown	22:40–06:10 (good, 7.5 h)	72.5° 03:05	10.08	80%	84.7°
2026-10-22 Thu	100	—	unknown	00:10–06:10 (good, 6.0 h)	72.5° 03:05	10.12	87%	71.8°
2026-10-23 Fri	96	—	unknown	03:10–06:15 (good, 3.08 h)	72.5° 03:00	10.16	94%	58.4°
2026-10-24 Sat	55	—	unknown	22:10–05:15 (marginal, 8.08 h)	72.5° 02:55	10.2	98%	44.7°
2026-10-25 Sun	29	—	unknown	02:10–05:15 (marginal, 3.08 h)	72.5° 01:50	10.24	100%	30.6°
2026-10-26 Mon	22	—	unknown	03:30–05:15 (marginal, 1.75 h)	72.5° 01:50	10.28	99%	16.2°
2026-10-27 Tue	22	—	unknown	20:50–22:40 (marginal, 1.83 h)	72.5° 01:45	10.31	96%	1.8°
2026-10-28 Wed	32	—	unknown	20:30–01:55 (marginal, 5.42 h)	72.5° 01:40	10.35	90%	13.1°
2026-10-29 Thu	48	—	unknown	20:10–05:20 (marginal, 9.17 h)	72.5° 01:35	10.39	81%	27.7°
2026-10-30 Fri	76	—	unknown	21:05–00:20 (good, 3.25 h)	72.5° 01:30	10.43	71%	42.2°
2026-10-31 Sat	89	—	unknown	20:20–04:30 (good, 8.17 h)	72.5° 01:30	10.47	60%	56.5°
2026-11-01 Sun	99	—	unknown	20:20–05:20 (good, 9.0 h)	72.5° 01:25	10.5	49%	70.6°
2026-11-02 Mon	100	—	unknown	20:15–05:25 (good, 9.17 h)	72.5° 01:20	10.54	38%	84.4°
2026-11-03 Tue	100	—	unknown	20:10–05:25 (good, 9.25 h)	72.5° 01:15	10.57	28%	97.9°
2026-11-04 Wed	100	—	unknown	20:05–05:25 (good, 9.33 h)	72.5° 01:10	10.61	19%	111.3°
2026-11-05 Thu	100	—	unknown	20:05–05:25 (good, 9.33 h)	72.5° 01:10	10.64	12%	124.4°
2026-11-06 Fri	100	—	unknown	20:00–05:30 (good, 9.5 h)	72.5° 01:05	10.68	6%	137.3°
2026-11-07 Sat	100	—	unknown	19:55–05:30 (good, 9.58 h)	72.5° 01:00	10.71	2%	150.0°
2026-11-08 Sun	100	—	unknown	19:50–05:30 (good, 9.67 h)	72.5° 00:55	10.74	0%	162.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-10-10&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.