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: 04-24 (68), 04-23 (66), 04-22 (62), 04-21 (58), 04-20 (52) — by astronomy; check the weather when the night is within four days.

2044-03-26astronomy score per night — click a bar for that night2044-04-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2044-04-09 Sat	45	—	unknown	03:15–05:15 (good, 2.0 h)	71.1° 08:05	7.6	94%	123.2°
2044-04-10 Sun	42	—	unknown	03:15–05:10 (good, 1.92 h)	71.1° 08:05	7.54	98%	115.7°
2044-04-11 Mon	40	—	unknown	03:15–05:10 (good, 1.92 h)	71.1° 08:00	7.49	100%	107.5°
2044-04-12 Tue	36	—	unknown	03:20–05:05 (good, 1.75 h)	71.1° 07:55	7.43	100%	98.9°
2044-04-13 Wed	33	—	unknown	03:25–05:05 (good, 1.67 h)	71.1° 07:50	7.37	98%	90.2°
2044-04-14 Thu	31	—	unknown	03:45–05:05 (good, 1.33 h)	71.1° 07:50	7.31	94%	81.6°
2044-04-15 Fri	30	—	unknown	03:50–05:00 (good, 1.17 h)	71.1° 07:45	7.26	88%	73.3°
2044-04-16 Sat	30	—	unknown	03:40–05:00 (good, 1.33 h)	71.1° 07:40	7.2	81%	65.6°
2044-04-17 Sun	32	—	unknown	03:10–04:55 (good, 1.75 h)	71.1° 07:35	7.14	73%	58.6°
2044-04-18 Mon	35	—	unknown	02:55–04:55 (good, 2.0 h)	71.1° 07:30	7.08	65%	52.7°
2044-04-19 Tue	46	—	unknown	02:25–04:55 (good, 2.5 h)	71.1° 07:30	7.02	55%	48.2°
2044-04-20 Wed	52	—	unknown	02:25–04:50 (good, 2.42 h)	71.1° 07:25	6.97	46%	45.8°
2044-04-21 Thu	58	—	unknown	02:20–04:50 (good, 2.5 h)	71.1° 07:20	6.91	36%	45.7°
2044-04-22 Fri	62	—	unknown	02:15–04:45 (good, 2.5 h)	71.1° 07:15	6.85	27%	48.2°
2044-04-23 Sat	66	—	unknown	02:10–04:45 (good, 2.58 h)	71.1° 07:10	6.79	18%	53.2°
2044-04-24 Sun	68	—	unknown	02:05–04:45 (good, 2.67 h)	71.1° 07:10	6.73	11%	60.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-03-26&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.