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: 02-29 (22), 03-01 (22), 03-02 (22), 02-27 (20), 02-28 (20) — by astronomy; check the weather when the night is within four days.

2044-02-02astronomy score per night — click a bar for that night2044-03-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-02-02 Tue	1	—	unknown	—	71.1° 11:30	10.74	14%	60.6°
2044-02-03 Wed	2	—	unknown	06:25–06:30 (marginal, 0.08 h)	71.1° 11:25	10.7	22%	68.8°
2044-02-04 Thu	2	—	unknown	06:20–06:30 (marginal, 0.17 h)	71.1° 11:25	10.67	32%	77.8°
2044-02-05 Fri	3	—	unknown	06:20–06:30 (marginal, 0.17 h)	71.1° 11:20	10.63	43%	87.3°
2044-02-06 Sat	3	—	unknown	06:15–06:30 (marginal, 0.25 h)	71.1° 11:15	10.6	54%	97.0°
2044-02-07 Sun	3	—	unknown	06:10–06:25 (marginal, 0.25 h)	71.1° 11:10	10.56	65%	106.7°
2044-02-08 Mon	4	—	unknown	05:40–05:55 (marginal, 0.25 h)	71.1° 11:05	10.53	76%	115.9°
2044-02-09 Tue	4	—	unknown	06:00–06:25 (marginal, 0.42 h)	71.1° 11:05	10.49	85%	124.1°
2044-02-10 Wed	5	—	unknown	05:30–05:50 (marginal, 0.33 h)	71.1° 11:00	10.45	92%	130.4°
2044-02-11 Thu	5	—	unknown	05:25–05:50 (marginal, 0.42 h)	71.1° 10:55	10.42	98%	134.0°
2044-02-12 Fri	5	—	unknown	05:25–05:50 (marginal, 0.42 h)	71.1° 10:50	10.38	100%	134.1°
2044-02-13 Sat	6	—	unknown	05:20–05:50 (marginal, 0.5 h)	71.1° 10:50	10.34	99%	130.9°
2044-02-14 Sun	6	—	unknown	05:15–05:45 (marginal, 0.5 h)	71.1° 10:45	10.3	96%	125.2°
2044-02-15 Mon	7	—	unknown	05:10–05:45 (marginal, 0.58 h)	71.1° 10:40	10.26	92%	117.9°
2044-02-16 Tue	7	—	unknown	05:05–05:45 (marginal, 0.67 h)	71.1° 10:35	10.22	85%	109.7°
2044-02-17 Wed	8	—	unknown	05:05–06:15 (marginal, 1.17 h)	71.1° 10:30	10.18	77%	101.2°
2044-02-18 Thu	8	—	unknown	05:00–05:40 (marginal, 0.67 h)	71.1° 10:30	10.14	68%	92.6°
2044-02-19 Fri	8	—	unknown	04:55–06:10 (marginal, 1.25 h)	71.1° 10:25	10.1	59%	84.1°
2044-02-20 Sat	10	—	unknown	05:35–05:40 (good, 0.08 h)	71.1° 10:20	10.06	49%	75.9°
2044-02-21 Sun	11	—	unknown	05:25–05:35 (good, 0.17 h)	71.1° 10:15	10.01	40%	68.1°
2044-02-22 Mon	12	—	unknown	05:20–05:35 (good, 0.25 h)	71.1° 10:10	9.97	31%	60.8°
2044-02-23 Tue	14	—	unknown	05:15–05:35 (good, 0.33 h)	71.1° 10:10	9.93	22%	54.5°
2044-02-24 Wed	17	—	unknown	05:05–05:35 (good, 0.5 h)	71.1° 10:05	9.89	15%	49.5°
2044-02-25 Thu	18	—	unknown	05:00–05:30 (good, 0.5 h)	71.1° 10:00	9.84	9%	46.3°
2044-02-26 Fri	18	—	unknown	04:55–05:30 (good, 0.58 h)	71.1° 09:55	9.8	4%	45.6°
2044-02-27 Sat	20	—	unknown	04:50–05:30 (good, 0.67 h)	71.1° 09:50	9.75	1%	47.5°
2044-02-28 Sun	20	—	unknown	04:45–05:25 (good, 0.67 h)	71.1° 09:50	9.71	0%	52.0°
2044-02-29 Mon	22	—	unknown	04:45–05:25 (good, 0.67 h)	71.1° 09:45	9.66	1%	58.5°
2044-03-01 Tue	22	—	unknown	04:40–05:25 (good, 0.75 h)	71.1° 09:40	9.62	5%	66.5°
2044-03-02 Wed	22	—	unknown	04:35–05:20 (good, 0.75 h)	71.1° 09:35	9.57	11%	75.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-02-02&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.