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: 02-06 (3), 02-07 (3), 02-05 (2), 01-09 (1), 01-10 (1) — by astronomy; check the weather when the night is within four days.

2032-01-09astronomy score per night — click a bar for that night2032-02-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2032-01-09 Fri	1	—	unknown	—	71.1° 13:10	11.35	12%	66.8°
2032-01-10 Sat	1	—	unknown	—	71.1° 13:05	11.33	5%	56.2°
2032-01-11 Sun	1	—	unknown	—	71.1° 13:00	11.31	1%	46.8°
2032-01-12 Mon	1	—	unknown	—	71.1° 12:55	11.3	0%	39.9°
2032-01-13 Tue	0	—	unknown	—	71.1° 12:55	11.28	2%	37.2°
2032-01-14 Wed	0	—	unknown	—	71.1° 12:50	11.26	7%	39.6°
2032-01-15 Thu	0	—	unknown	—	71.1° 12:45	11.23	14%	46.3°
2032-01-16 Fri	0	—	unknown	—	71.1° 12:40	11.21	23%	55.2°
2032-01-17 Sat	0	—	unknown	—	71.1° 12:35	11.19	33%	65.3°
2032-01-18 Sun	0	—	unknown	—	71.1° 12:35	11.17	44%	75.8°
2032-01-19 Mon	0	—	unknown	—	71.1° 12:30	11.14	55%	86.2°
2032-01-20 Tue	0	—	unknown	—	71.1° 12:25	11.12	65%	96.4°
2032-01-21 Wed	0	—	unknown	—	71.1° 12:20	11.09	74%	106.3°
2032-01-22 Thu	0	—	unknown	—	71.1° 12:20	11.07	82%	115.7°
2032-01-23 Fri	0	—	unknown	—	71.1° 12:15	11.04	89%	124.3°
2032-01-24 Sat	0	—	unknown	—	71.1° 12:10	11.01	94%	132.0°
2032-01-25 Sun	0	—	unknown	—	71.1° 12:05	10.99	98%	138.0°
2032-01-26 Mon	0	—	unknown	—	71.1° 12:00	10.96	100%	141.9°
2032-01-27 Tue	0	—	unknown	—	71.1° 11:55	10.93	100%	142.7°
2032-01-28 Wed	1	—	unknown	—	71.1° 11:50	10.9	98%	140.4°
2032-01-29 Thu	1	—	unknown	—	71.1° 11:45	10.87	95%	135.5°
2032-01-30 Fri	1	—	unknown	—	71.1° 11:40	10.84	90%	128.6°
2032-01-31 Sat	1	—	unknown	—	71.1° 11:40	10.8	83%	120.4°
2032-02-01 Sun	1	—	unknown	—	71.1° 11:35	10.77	76%	111.4°
2032-02-02 Mon	1	—	unknown	—	71.1° 11:30	10.74	66%	101.8°
2032-02-03 Tue	1	—	unknown	—	71.1° 11:25	10.71	57%	91.7°
2032-02-04 Wed	1	—	unknown	—	71.1° 11:25	10.67	46%	81.3°
2032-02-05 Thu	2	—	unknown	05:50–05:55 (marginal, 0.08 h)	71.1° 11:20	10.64	36%	70.7°
2032-02-06 Fri	3	—	unknown	05:45–05:55 (marginal, 0.17 h)	71.1° 11:15	10.6	25%	60.3°
2032-02-07 Sat	3	—	unknown	05:45–05:55 (marginal, 0.17 h)	71.1° 11:10	10.57	16%	50.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2032-01-09&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.