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: 01-06 (100), 01-07 (100), 01-08 (100), 01-09 (100), 01-10 (100) — by astronomy; check the weather when the night is within four days.

2045-01-06astronomy score per night — click a bar for that night2045-02-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-01-06 Fri	100	—	unknown	18:50–01:50 (good, 7.0 h)	72.6° 21:05	11.38	83%	96.3°
2045-01-07 Sat	100	—	unknown	18:50–02:00 (good, 7.17 h)	72.6° 21:00	11.37	73%	110.6°
2045-01-08 Sun	100	—	unknown	18:50–02:00 (good, 7.17 h)	72.6° 20:55	11.35	63%	124.5°
2045-01-09 Mon	100	—	unknown	18:50–02:00 (good, 7.17 h)	72.6° 20:50	11.33	52%	137.9°
2045-01-10 Tue	100	—	unknown	18:50–01:55 (good, 7.08 h)	72.6° 20:45	11.32	42%	150.8°
2045-01-11 Wed	100	—	unknown	18:55–01:55 (good, 7.0 h)	72.6° 20:45	11.3	32%	163.5°
2045-01-12 Thu	100	—	unknown	18:55–01:50 (good, 6.92 h)	72.6° 20:40	11.28	23%	175.8°
2045-01-13 Fri	100	—	unknown	18:55–01:45 (good, 6.83 h)	72.6° 20:35	11.26	16%	171.9°
2045-01-14 Sat	100	—	unknown	18:55–01:45 (good, 6.83 h)	72.6° 20:30	11.24	9%	159.9°
2045-01-15 Sun	100	—	unknown	18:55–01:40 (good, 6.75 h)	72.6° 20:30	11.22	5%	148.0°
2045-01-16 Mon	100	—	unknown	19:00–01:35 (good, 6.58 h)	72.6° 20:25	11.19	2%	136.1°
2045-01-17 Tue	100	—	unknown	19:00–01:30 (good, 6.5 h)	72.6° 20:20	11.17	0%	124.3°
2045-01-18 Wed	100	—	unknown	19:00–01:25 (good, 6.42 h)	72.6° 20:15	11.15	0%	112.5°
2045-01-19 Thu	100	—	unknown	19:00–01:25 (good, 6.42 h)	72.6° 20:10	11.12	3%	100.6°
2045-01-20 Fri	100	—	unknown	19:00–01:20 (good, 6.33 h)	72.6° 20:10	11.1	7%	88.7°
2045-01-21 Sat	100	—	unknown	19:05–01:15 (good, 6.17 h)	72.6° 20:05	11.07	12%	76.7°
2045-01-22 Sun	100	—	unknown	19:05–01:10 (good, 6.08 h)	72.6° 20:00	11.05	19%	64.5°
2045-01-23 Mon	95	—	unknown	19:05–01:05 (good, 6.0 h)	72.6° 19:55	11.02	27%	52.2°
2045-01-24 Tue	86	—	unknown	19:05–01:05 (good, 6.0 h)	72.6° 19:50	10.99	37%	39.6°
2045-01-25 Wed	71	—	unknown	19:05–00:40 (good, 5.58 h)	72.6° 19:50	10.96	47%	26.7°
2045-01-26 Thu	56	—	unknown	21:35–22:05 (good, 0.5 h)	72.6° 19:45	10.93	58%	13.4°
2045-01-27 Fri	37	—	unknown	19:10–01:10 (marginal, 6.0 h)	72.6° 19:40	10.9	68%	1.2°
2045-01-28 Sat	24	—	unknown	19:10–00:45 (marginal, 5.58 h)	72.6° 19:35	10.87	78%	14.6°
2045-01-29 Sun	17	—	unknown	19:10–22:15 (marginal, 3.08 h)	72.6° 19:35	10.84	87%	29.1°
2045-01-30 Mon	23	—	unknown	19:10–23:50 (marginal, 4.67 h)	72.6° 19:30	10.81	94%	44.1°
2045-01-31 Tue	36	—	unknown	19:15–00:25 (marginal, 5.17 h)	72.6° 19:25	10.78	99%	59.3°
2045-02-01 Wed	55	—	unknown	19:15–21:15 (good, 2.0 h)	72.6° 19:20	10.74	100%	74.5°
2045-02-02 Thu	78	—	unknown	19:15–23:00 (good, 3.75 h)	72.6° 19:15	10.71	98%	89.7°
2045-02-03 Fri	100	—	unknown	19:15–00:00 (good, 4.75 h)	72.6° 19:15	10.68	94%	104.6°
2045-02-04 Sat	100	—	unknown	19:20–00:10 (good, 4.83 h)	72.6° 19:10	10.64	87%	119.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-01-06&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.