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: 04-06 (50), 04-03 (49), 04-05 (49), 04-07 (49), 04-01 (48) — by astronomy; check the weather when the night is within four days.

2044-03-10astronomy score per night — click a bar for that night2044-04-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-03-10 Thu	25	—	unknown	04:10–05:10 (good, 1.0 h)	71.1° 09:05	9.19	90%	134.5°
2044-03-11 Fri	24	—	unknown	04:10–05:05 (good, 0.92 h)	71.1° 09:00	9.14	96%	132.5°
2044-03-12 Sat	25	—	unknown	04:05–05:05 (good, 1.0 h)	71.1° 08:55	9.09	99%	127.7°
2044-03-13 Sun	25	—	unknown	04:05–05:05 (good, 1.0 h)	71.1° 08:55	9.04	100%	120.9°
2044-03-14 Mon	23	—	unknown	04:05–05:00 (good, 0.92 h)	71.1° 08:50	8.99	99%	113.0°
2044-03-15 Tue	22	—	unknown	04:05–05:00 (good, 0.92 h)	71.1° 08:45	8.94	95%	104.5°
2044-03-16 Wed	21	—	unknown	04:05–05:00 (good, 0.92 h)	71.1° 08:40	8.89	90%	95.8°
2044-03-17 Thu	20	—	unknown	04:00–04:55 (good, 0.92 h)	71.1° 08:40	8.84	83%	87.2°
2044-03-18 Fri	21	—	unknown	03:55–04:55 (good, 1.0 h)	71.1° 08:35	8.79	75%	78.8°
2044-03-19 Sat	22	—	unknown	03:50–04:55 (good, 1.08 h)	71.1° 08:30	8.74	66%	70.7°
2044-03-20 Sun	23	—	unknown	03:45–04:50 (good, 1.08 h)	71.1° 08:25	8.69	57%	63.3°
2044-03-21 Mon	25	—	unknown	03:35–04:50 (good, 1.25 h)	71.1° 08:20	8.64	48%	56.6°
2044-03-22 Tue	29	—	unknown	03:15–04:45 (good, 1.5 h)	71.1° 08:20	8.58	38%	51.1°
2044-03-23 Wed	36	—	unknown	03:15–04:45 (good, 1.5 h)	71.1° 08:15	8.53	29%	47.2°
2044-03-24 Thu	39	—	unknown	03:10–04:45 (good, 1.58 h)	71.1° 08:10	8.48	21%	45.6°
2044-03-25 Fri	40	—	unknown	03:05–04:40 (good, 1.58 h)	71.1° 08:05	8.43	13%	46.5°
2044-03-26 Sat	42	—	unknown	04:00–05:40 (good, 1.67 h)	71.1° 09:00	8.37	7%	50.0°
2044-03-27 Sun	43	—	unknown	03:55–05:40 (good, 1.75 h)	71.1° 09:00	8.32	3%	55.9°
2044-03-28 Mon	43	—	unknown	03:55–05:35 (good, 1.67 h)	71.1° 08:55	8.27	0%	63.5°
2044-03-29 Tue	45	—	unknown	03:50–05:35 (good, 1.75 h)	71.1° 08:50	8.21	0%	72.3°
2044-03-30 Wed	44	—	unknown	03:45–05:30 (good, 1.75 h)	71.1° 08:45	8.16	3%	82.0°
2044-03-31 Thu	46	—	unknown	03:40–05:30 (good, 1.83 h)	71.1° 08:45	8.1	8%	92.0°
2044-04-01 Fri	48	—	unknown	03:35–05:30 (good, 1.92 h)	71.1° 08:40	8.05	16%	102.0°
2044-04-02 Sat	47	—	unknown	03:35–05:25 (good, 1.83 h)	71.1° 08:35	7.99	25%	111.6°
2044-04-03 Sun	49	—	unknown	03:30–05:25 (good, 1.92 h)	71.1° 08:30	7.94	36%	120.2°
2044-04-04 Mon	48	—	unknown	03:25–05:20 (good, 1.92 h)	71.1° 08:25	7.88	47%	127.4°
2044-04-05 Tue	49	—	unknown	03:25–05:20 (good, 1.92 h)	71.1° 08:25	7.83	59%	132.4°
2044-04-06 Wed	50	—	unknown	03:25–05:20 (good, 1.92 h)	71.1° 08:20	7.77	70%	134.5°
2044-04-07 Thu	49	—	unknown	03:20–05:15 (good, 1.92 h)	71.1° 08:15	7.71	79%	133.3°
2044-04-08 Fri	45	—	unknown	03:20–05:15 (good, 1.92 h)	71.1° 08:10	7.66	87%	129.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-03-10&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.