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: 12-14 (100), 12-15 (100), 12-26 (100), 12-27 (100), 12-28 (100) — by astronomy; check the weather when the night is within four days.

2045-12-14astronomy score per night — click a bar for that night2046-01-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-12-14 Thu	100	—	unknown	18:35–03:45 (good, 9.17 h)	72.6° 22:35	11.49	35%	83.8°
2045-12-15 Fri	100	—	unknown	18:35–03:40 (good, 9.08 h)	72.6° 22:30	11.49	44%	72.0°
2045-12-16 Sat	98	—	unknown	18:35–03:40 (good, 9.08 h)	72.6° 22:25	11.5	54%	60.1°
2045-12-17 Sun	90	—	unknown	20:00–03:35 (good, 7.58 h)	72.6° 22:25	11.5	63%	48.0°
2045-12-18 Mon	82	—	unknown	00:10–02:30 (good, 2.33 h)	72.6° 22:20	11.5	72%	35.7°
2045-12-19 Tue	50	—	unknown	18:35–03:45 (marginal, 9.17 h)	72.6° 22:15	11.51	81%	23.1°
2045-12-20 Wed	35	—	unknown	18:35–03:30 (marginal, 8.92 h)	72.6° 22:10	11.51	88%	10.1°
2045-12-21 Thu	23	—	unknown	00:55–03:05 (marginal, 2.17 h)	72.6° 22:05	11.51	94%	3.4°
2045-12-22 Fri	21	—	unknown	18:35–20:15 (marginal, 1.67 h)	72.6° 22:05	11.51	98%	17.1°
2045-12-23 Sat	25	—	unknown	18:40–21:10 (marginal, 2.5 h)	72.6° 22:00	11.5	100%	31.3°
2045-12-24 Sun	48	—	unknown	18:40–01:20 (marginal, 6.67 h)	72.6° 21:55	11.5	99%	45.7°
2045-12-25 Mon	66	—	unknown	18:40–21:15 (good, 2.58 h)	72.6° 21:50	11.5	95%	60.3°
2045-12-26 Tue	100	—	unknown	18:40–00:30 (good, 5.83 h)	72.6° 21:45	11.49	89%	75.0°
2045-12-27 Wed	100	—	unknown	18:40–02:15 (good, 7.58 h)	72.6° 21:45	11.49	80%	89.6°
2045-12-28 Thu	100	—	unknown	18:40–02:35 (good, 7.92 h)	72.6° 21:40	11.48	70%	104.0°
2045-12-29 Fri	100	—	unknown	18:40–02:40 (good, 8.0 h)	72.6° 21:35	11.48	59%	118.3°
2045-12-30 Sat	100	—	unknown	18:40–02:40 (good, 8.0 h)	72.6° 21:30	11.47	48%	132.3°
2045-12-31 Sun	100	—	unknown	18:45–02:35 (good, 7.83 h)	72.6° 21:30	11.46	37%	146.0°
2046-01-01 Mon	100	—	unknown	18:45–02:35 (good, 7.83 h)	72.6° 21:25	11.45	27%	159.6°
2046-01-02 Tue	100	—	unknown	18:45–02:30 (good, 7.75 h)	72.6° 21:20	11.44	18%	172.8°
2046-01-03 Wed	100	—	unknown	18:45–02:25 (good, 7.67 h)	72.6° 21:15	11.43	11%	173.9°
2046-01-04 Thu	100	—	unknown	18:45–02:25 (good, 7.67 h)	72.6° 21:10	11.41	5%	161.1°
2046-01-05 Fri	100	—	unknown	18:45–02:20 (good, 7.58 h)	72.6° 21:10	11.4	2%	148.4°
2046-01-06 Sat	100	—	unknown	18:50–02:15 (good, 7.42 h)	72.6° 21:05	11.39	0%	135.9°
2046-01-07 Sun	100	—	unknown	18:50–02:10 (good, 7.33 h)	72.6° 21:00	11.37	1%	123.6°
2046-01-08 Mon	100	—	unknown	18:50–02:05 (good, 7.25 h)	72.6° 20:55	11.36	3%	111.4°
2046-01-09 Tue	100	—	unknown	18:50–02:05 (good, 7.25 h)	72.6° 20:50	11.34	7%	99.4°
2046-01-10 Wed	100	—	unknown	18:50–02:00 (good, 7.17 h)	72.6° 20:50	11.32	12%	87.5°
2046-01-11 Thu	100	—	unknown	18:50–01:55 (good, 7.08 h)	72.6° 20:45	11.3	19%	75.7°
2046-01-12 Fri	100	—	unknown	18:55–01:50 (good, 6.92 h)	72.6° 20:40	11.28	27%	63.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-12-14&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.