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 HD 189733: 02-08 (5), 02-09 (5), 02-07 (4), 02-04 (3), 02-05 (3) — by astronomy; check the weather when the night is within four days.

2033-01-11astronomy score per night — click a bar for that night2033-02-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-01-11 Tue	0	—	unknown	—	71.1° 13:00	11.3	87%	114.6°
2033-01-12 Wed	0	—	unknown	—	71.1° 12:55	11.28	93%	124.0°
2033-01-13 Thu	0	—	unknown	—	71.1° 12:50	11.26	97%	132.2°
2033-01-14 Fri	0	—	unknown	—	71.1° 12:45	11.24	99%	138.5°
2033-01-15 Sat	0	—	unknown	—	71.1° 12:40	11.22	100%	142.1°
2033-01-16 Sun	0	—	unknown	—	71.1° 12:40	11.2	98%	142.4°
2033-01-17 Mon	0	—	unknown	—	71.1° 12:35	11.17	94%	139.5°
2033-01-18 Tue	0	—	unknown	—	71.1° 12:30	11.15	89%	134.0°
2033-01-19 Wed	0	—	unknown	—	71.1° 12:25	11.12	83%	126.9°
2033-01-20 Thu	0	—	unknown	—	71.1° 12:25	11.1	75%	118.7°
2033-01-21 Fri	0	—	unknown	—	71.1° 12:20	11.07	67%	109.9°
2033-01-22 Sat	0	—	unknown	—	71.1° 12:15	11.05	58%	100.6°
2033-01-23 Sun	0	—	unknown	—	71.1° 12:10	11.02	48%	91.0°
2033-01-24 Mon	0	—	unknown	—	71.1° 12:05	10.99	38%	81.2°
2033-01-25 Tue	0	—	unknown	—	71.1° 12:00	10.96	29%	71.3°
2033-01-26 Wed	0	—	unknown	—	71.1° 11:55	10.93	20%	61.4°
2033-01-27 Thu	0	—	unknown	—	71.1° 11:50	10.91	12%	52.1°
2033-01-28 Fri	1	—	unknown	—	71.1° 11:45	10.87	6%	44.0°
2033-01-29 Sat	1	—	unknown	—	71.1° 11:45	10.84	2%	38.6°
2033-01-30 Sun	1	—	unknown	—	71.1° 11:40	10.81	0%	37.5°
2033-01-31 Mon	1	—	unknown	—	71.1° 11:35	10.78	2%	41.2°
2033-02-01 Tue	1	—	unknown	—	71.1° 11:30	10.75	6%	48.7°
2033-02-02 Wed	1	—	unknown	06:25–06:30 (marginal, 0.08 h)	71.1° 11:30	10.71	13%	58.4°
2033-02-03 Thu	2	—	unknown	05:55–06:00 (marginal, 0.08 h)	71.1° 11:25	10.68	22%	69.2°
2033-02-04 Fri	3	—	unknown	06:20–06:30 (marginal, 0.17 h)	71.1° 11:20	10.65	32%	80.4°
2033-02-05 Sat	3	—	unknown	06:15–06:30 (marginal, 0.25 h)	71.1° 11:15	10.61	43%	91.5°
2033-02-06 Sun	3	—	unknown	06:10–06:25 (marginal, 0.25 h)	71.1° 11:10	10.58	54%	102.3°
2033-02-07 Mon	4	—	unknown	05:40–05:55 (marginal, 0.25 h)	71.1° 11:10	10.54	65%	112.6°
2033-02-08 Tue	5	—	unknown	05:35–05:55 (marginal, 0.33 h)	71.1° 11:05	10.5	74%	122.1°
2033-02-09 Wed	5	—	unknown	05:30–05:50 (marginal, 0.33 h)	71.1° 11:00	10.47	82%	130.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-01-11&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.