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: 12-21 (100), 12-22 (100), 01-03 (100), 01-04 (100), 01-05 (100) — by astronomy; check the weather when the night is within four days.

2047-12-21astronomy score per night — click a bar for that night2048-01-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-12-21 Sat	100	—	unknown	18:35–03:20 (good, 8.75 h)	72.6° 22:10	11.51	29%	84.6°
2047-12-22 Sun	100	—	unknown	18:35–03:15 (good, 8.67 h)	72.6° 22:05	11.51	39%	71.7°
2047-12-23 Mon	98	—	unknown	18:40–03:10 (good, 8.5 h)	72.6° 22:00	11.51	48%	59.2°
2047-12-24 Tue	90	—	unknown	19:10–03:10 (good, 8.0 h)	72.6° 21:55	11.5	58%	47.0°
2047-12-25 Wed	82	—	unknown	23:15–03:05 (good, 3.83 h)	72.6° 21:55	11.5	68%	35.0°
2047-12-26 Thu	52	—	unknown	18:40–03:30 (marginal, 8.83 h)	72.6° 21:50	11.5	76%	23.2°
2047-12-27 Fri	39	—	unknown	18:40–03:10 (marginal, 8.5 h)	72.6° 21:45	11.49	84%	11.4°
2047-12-28 Sat	27	—	unknown	18:40–02:50 (marginal, 8.17 h)	72.6° 21:40	11.49	90%	1.1°
2047-12-29 Sun	22	—	unknown	18:40–20:15 (marginal, 1.58 h)	72.6° 21:40	11.48	95%	12.5°
2047-12-30 Mon	22	—	unknown	18:40–20:25 (marginal, 1.75 h)	72.6° 21:35	11.47	98%	24.4°
2047-12-31 Tue	30	—	unknown	18:45–22:10 (marginal, 3.42 h)	72.6° 21:30	11.46	100%	36.6°
2048-01-01 Wed	49	—	unknown	18:45–01:55 (marginal, 7.17 h)	72.6° 21:25	11.45	100%	48.9°
2048-01-02 Thu	67	—	unknown	18:45–20:55 (good, 2.17 h)	72.6° 21:20	11.44	97%	61.4°
2048-01-03 Fri	100	—	unknown	18:45–23:40 (good, 4.92 h)	72.6° 21:20	11.43	93%	74.1°
2048-01-04 Sat	100	—	unknown	18:45–01:15 (good, 6.5 h)	72.6° 21:15	11.42	87%	86.9°
2048-01-05 Sun	100	—	unknown	18:45–02:00 (good, 7.25 h)	72.6° 21:10	11.41	79%	100.0°
2048-01-06 Mon	100	—	unknown	18:50–02:05 (good, 7.25 h)	72.6° 21:05	11.39	70%	113.3°
2048-01-07 Tue	100	—	unknown	18:50–02:10 (good, 7.33 h)	72.6° 21:00	11.38	59%	126.8°
2048-01-08 Wed	100	—	unknown	18:50–02:05 (good, 7.25 h)	72.6° 21:00	11.36	48%	140.6°
2048-01-09 Thu	100	—	unknown	18:50–02:05 (good, 7.25 h)	72.6° 20:55	11.35	37%	154.7°
2048-01-10 Fri	100	—	unknown	18:50–02:00 (good, 7.17 h)	72.6° 20:50	11.33	26%	169.0°
2048-01-11 Sat	100	—	unknown	18:50–01:55 (good, 7.08 h)	72.6° 20:45	11.31	17%	176.3°
2048-01-12 Sun	100	—	unknown	18:55–01:55 (good, 7.0 h)	72.6° 20:45	11.29	9%	161.8°
2048-01-13 Mon	100	—	unknown	18:55–01:50 (good, 6.92 h)	72.6° 20:40	11.27	3%	147.1°
2048-01-14 Tue	100	—	unknown	18:55–01:45 (good, 6.83 h)	72.6° 20:35	11.25	0%	132.4°
2048-01-15 Wed	100	—	unknown	18:55–01:40 (good, 6.75 h)	72.6° 20:30	11.23	0%	118.0°
2048-01-16 Thu	100	—	unknown	18:55–01:40 (good, 6.75 h)	72.6° 20:25	11.21	3%	103.8°
2048-01-17 Fri	100	—	unknown	19:00–01:35 (good, 6.58 h)	72.6° 20:25	11.19	8%	90.0°
2048-01-18 Sat	100	—	unknown	19:00–01:30 (good, 6.5 h)	72.6° 20:20	11.16	14%	76.7°
2048-01-19 Sun	100	—	unknown	19:00–01:25 (good, 6.42 h)	72.6° 20:15	11.14	22%	63.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-12-21&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.