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: 01-22 (100), 02-03 (100), 02-04 (100), 02-05 (100), 02-06 (100) — by astronomy; check the weather when the night is within four days.

2045-01-22astronomy score per night — click a bar for that night2045-02-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2045-02-05 Sun	100	—	unknown	19:20–00:10 (good, 4.83 h)	72.6° 19:05	10.61	78%	133.2°
2045-02-06 Mon	100	—	unknown	19:20–00:05 (good, 4.75 h)	72.6° 19:00	10.57	69%	146.7°
2045-02-07 Tue	100	—	unknown	19:20–00:10 (good, 4.83 h)	72.6° 18:55	10.54	59%	159.8°
2045-02-08 Wed	100	—	unknown	19:20–00:05 (good, 4.75 h)	72.6° 18:55	10.5	48%	172.5°
2045-02-09 Thu	100	—	unknown	19:25–00:00 (good, 4.58 h)	72.6° 18:50	10.46	39%	174.9°
2045-02-10 Fri	100	—	unknown	19:25–23:55 (good, 4.5 h)	72.6° 18:45	10.42	30%	162.9°
2045-02-11 Sat	100	—	unknown	19:25–23:50 (good, 4.42 h)	72.6° 18:40	10.39	21%	151.0°
2045-02-12 Sun	100	—	unknown	19:25–23:50 (good, 4.42 h)	72.6° 18:40	10.35	14%	139.2°
2045-02-13 Mon	100	—	unknown	19:30–23:45 (good, 4.25 h)	72.6° 18:35	10.31	8%	127.3°
2045-02-14 Tue	100	—	unknown	19:30–23:40 (good, 4.17 h)	72.6° 18:30	10.27	4%	115.5°
2045-02-15 Wed	100	—	unknown	19:30–23:35 (good, 4.08 h)	72.6° 18:25	10.23	1%	103.7°
2045-02-16 Thu	100	—	unknown	19:30–23:35 (good, 4.08 h)	72.6° 18:20	10.19	0%	91.7°
2045-02-17 Fri	100	—	unknown	19:35–23:30 (good, 3.92 h)	72.6° 18:20	10.15	1%	79.6°
2045-02-18 Sat	100	—	unknown	19:35–23:25 (good, 3.83 h)	72.6° 18:15	10.11	4%	67.4°
2045-02-19 Sun	95	—	unknown	19:35–23:20 (good, 3.75 h)	72.6° 18:10	10.07	8%	55.1°
2045-02-20 Mon	87	—	unknown	19:35–23:15 (good, 3.67 h)	72.6° 18:05	10.02	14%	42.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-01-22&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.