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 Seven Sisters: 08-21 (78), 08-20 (74), 08-19 (66), 08-18 (54), 08-17 (42) — by astronomy; check the weather when the night is within four days.

2044-07-23astronomy score per night — click a bar for that night2044-08-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-07-23 Sat	15	—	unknown	03:55–04:10 (good, 0.25 h)	72.6° 09:00	5.4	1%	50.8°
2044-07-24 Sun	18	—	unknown	03:50–04:15 (good, 0.42 h)	72.6° 08:55	5.45	0%	65.9°
2044-07-25 Mon	19	—	unknown	03:45–04:15 (good, 0.5 h)	72.6° 08:50	5.51	2%	80.8°
2044-07-26 Tue	21	—	unknown	03:40–04:15 (good, 0.58 h)	72.6° 08:50	5.56	7%	95.4°
2044-07-27 Wed	24	—	unknown	03:40–04:20 (good, 0.67 h)	72.6° 08:45	5.61	14%	109.6°
2044-07-28 Thu	25	—	unknown	03:35–04:20 (good, 0.75 h)	72.6° 08:40	5.67	22%	123.3°
2044-07-29 Fri	26	—	unknown	03:30–04:20 (good, 0.83 h)	72.6° 08:35	5.72	32%	136.6°
2044-07-30 Sat	28	—	unknown	03:25–04:25 (good, 1.0 h)	72.6° 08:30	5.77	42%	149.4°
2044-07-31 Sun	30	—	unknown	03:20–04:25 (good, 1.08 h)	72.6° 08:30	5.83	52%	161.9°
2044-08-01 Mon	32	—	unknown	03:20–04:25 (good, 1.08 h)	72.6° 08:25	5.88	62%	174.0°
2044-08-02 Tue	35	—	unknown	03:15–04:30 (good, 1.25 h)	72.6° 08:20	5.94	71%	173.8°
2044-08-03 Wed	36	—	unknown	03:10–04:30 (good, 1.33 h)	72.6° 08:15	5.99	79%	161.9°
2044-08-04 Thu	38	—	unknown	03:05–04:30 (good, 1.42 h)	72.5° 08:10	6.05	86%	150.1°
2044-08-05 Fri	40	—	unknown	03:10–04:35 (good, 1.42 h)	72.6° 08:10	6.11	92%	138.3°
2044-08-06 Sat	40	—	unknown	03:05–04:35 (good, 1.5 h)	72.6° 08:05	6.16	96%	126.4°
2044-08-07 Sun	35	—	unknown	03:05–04:35 (good, 1.5 h)	72.6° 08:00	6.22	99%	114.4°
2044-08-08 Mon	31	—	unknown	03:10–04:40 (good, 1.5 h)	72.6° 07:55	6.28	100%	102.3°
2044-08-09 Tue	26	—	unknown	03:45–04:40 (good, 0.92 h)	72.6° 07:55	6.33	99%	90.1°
2044-08-10 Wed	21	—	unknown	02:25–04:40 (marginal, 2.25 h)	72.6° 07:50	6.39	96%	77.6°
2044-08-11 Thu	17	—	unknown	02:30–04:40 (marginal, 2.17 h)	72.6° 07:45	6.45	91%	65.0°
2044-08-12 Fri	15	—	unknown	02:30–04:45 (marginal, 2.25 h)	72.6° 07:40	6.51	84%	52.2°
2044-08-13 Sat	14	—	unknown	02:25–04:45 (marginal, 2.33 h)	72.6° 07:35	6.56	76%	39.1°
2044-08-14 Sun	16	—	unknown	02:15–04:45 (marginal, 2.5 h)	72.6° 07:35	6.62	66%	25.8°
2044-08-15 Mon	23	—	unknown	02:00–04:50 (marginal, 2.83 h)	72.6° 07:30	6.68	55%	12.3°
2044-08-16 Tue	32	—	unknown	03:05–04:50 (good, 1.75 h)	72.6° 07:25	6.74	44%	2.0°
2044-08-17 Wed	42	—	unknown	02:30–04:50 (good, 2.33 h)	72.6° 07:20	6.79	33%	15.8°
2044-08-18 Thu	54	—	unknown	02:20–04:55 (good, 2.58 h)	72.5° 07:15	6.85	22%	30.2°
2044-08-19 Fri	66	—	unknown	02:10–04:55 (good, 2.75 h)	72.6° 07:15	6.91	13%	44.9°
2044-08-20 Sat	74	—	unknown	02:05–04:55 (good, 2.83 h)	72.6° 07:10	6.97	6%	59.6°
2044-08-21 Sun	78	—	unknown	02:00–04:55 (good, 2.92 h)	72.6° 07:05	7.02	2%	74.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-07-23&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.