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: 01-02 (6), 01-03 (5), 01-04 (3), 01-05 (2), 01-06 (1) — by astronomy; check the weather when the night is within four days.

2033-01-02astronomy score per night — click a bar for that night2033-01-31

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-01-02 Sun	6	—	unknown	18:10–18:40 (marginal, 0.5 h)	71.1° 13:35	11.44	3%	37.5°
2033-01-03 Mon	5	—	unknown	18:45–19:05 (marginal, 0.33 h)	71.1° 13:30	11.42	9%	38.3°
2033-01-04 Tue	3	—	unknown	18:45–19:00 (marginal, 0.25 h)	71.1° 13:25	11.41	16%	43.5°
2033-01-05 Wed	2	—	unknown	18:45–18:55 (marginal, 0.17 h)	71.1° 13:20	11.4	26%	51.6°
2033-01-06 Thu	1	—	unknown	—	71.1° 13:20	11.38	36%	61.4°
2033-01-07 Fri	1	—	unknown	—	71.1° 13:15	11.37	48%	72.1°
2033-01-08 Sat	1	—	unknown	—	71.1° 13:10	11.35	59%	83.0°
2033-01-09 Sun	1	—	unknown	—	71.1° 13:05	11.34	69%	93.8°
2033-01-10 Mon	0	—	unknown	—	71.1° 13:00	11.32	79%	104.5°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-01-02&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.