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: 10-25 (100), 10-26 (100), 10-27 (100), 10-28 (100), 10-29 (100) — by astronomy; check the weather when the night is within four days.

2043-10-19astronomy score per night — click a bar for that night2043-11-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-10-19 Mon	21	—	unknown	04:50–06:10 (marginal, 1.33 h)	72.6° 03:15	9.99	97%	13.5°
2043-10-20 Tue	25	—	unknown	22:10–02:00 (marginal, 3.83 h)	72.5° 03:15	10.03	91%	1.6°
2043-10-21 Wed	37	—	unknown	21:50–06:10 (marginal, 8.33 h)	72.6° 03:10	10.07	84%	16.4°
2043-10-22 Thu	54	—	unknown	21:35–06:10 (marginal, 8.58 h)	72.6° 03:05	10.11	74%	30.9°
2043-10-23 Fri	81	—	unknown	21:55–04:05 (good, 6.17 h)	72.6° 03:00	10.15	63%	45.2°
2043-10-24 Sat	91	—	unknown	21:50–05:15 (good, 8.42 h)	72.5° 02:55	10.19	52%	59.1°
2043-10-25 Sun	100	—	unknown	20:45–05:15 (good, 8.5 h)	72.5° 01:55	10.23	41%	72.7°
2043-10-26 Mon	100	—	unknown	20:45–05:15 (good, 8.5 h)	72.6° 01:50	10.27	31%	85.9°
2043-10-27 Tue	100	—	unknown	20:40–05:15 (good, 8.58 h)	72.6° 01:45	10.31	22%	98.9°
2043-10-28 Wed	100	—	unknown	20:35–05:20 (good, 8.75 h)	72.6° 01:40	10.35	14%	111.6°
2043-10-29 Thu	100	—	unknown	20:30–05:20 (good, 8.83 h)	72.5° 01:35	10.39	8%	124.1°
2043-10-30 Fri	100	—	unknown	20:25–05:20 (good, 8.92 h)	72.6° 01:35	10.42	3%	136.4°
2043-10-31 Sat	100	—	unknown	20:25–05:20 (good, 8.92 h)	72.6° 01:30	10.46	1%	148.6°
2043-11-01 Sun	100	—	unknown	20:20–05:20 (good, 9.0 h)	72.6° 01:25	10.5	0%	160.6°
2043-11-02 Mon	100	—	unknown	20:15–05:25 (good, 9.17 h)	72.6° 01:20	10.53	1%	172.5°
2043-11-03 Tue	100	—	unknown	20:10–05:25 (good, 9.25 h)	72.5° 01:20	10.57	4%	175.6°
2043-11-04 Wed	100	—	unknown	20:10–05:25 (good, 9.25 h)	72.6° 01:15	10.6	8%	163.8°
2043-11-05 Thu	100	—	unknown	20:05–05:25 (good, 9.33 h)	72.6° 01:10	10.64	14%	152.0°
2043-11-06 Fri	100	—	unknown	20:00–05:30 (good, 9.5 h)	72.6° 01:05	10.67	22%	140.1°
2043-11-07 Sat	100	—	unknown	20:00–05:30 (good, 9.5 h)	72.5° 01:00	10.71	30%	128.2°
2043-11-08 Sun	100	—	unknown	19:55–05:30 (good, 9.58 h)	72.5° 01:00	10.74	39%	116.0°
2043-11-09 Mon	100	—	unknown	19:55–05:30 (good, 9.58 h)	72.6° 00:55	10.77	49%	103.6°
2043-11-10 Tue	100	—	unknown	20:00–05:30 (good, 9.5 h)	72.6° 00:50	10.8	59%	90.9°
2043-11-11 Wed	100	—	unknown	20:15–05:35 (good, 9.33 h)	72.6° 00:45	10.84	69%	77.7°
2043-11-12 Thu	100	—	unknown	22:00–05:35 (good, 7.58 h)	72.5° 00:40	10.87	79%	64.1°
2043-11-13 Fri	91	—	unknown	01:40–05:35 (good, 3.92 h)	72.6° 00:40	10.9	87%	49.9°
2043-11-14 Sat	81	—	unknown	05:05–05:35 (good, 0.5 h)	72.6° 00:35	10.93	94%	35.4°
2043-11-15 Sun	34	—	unknown	01:30–05:35 (marginal, 4.08 h)	72.6° 00:30	10.96	98%	20.4°
2043-11-16 Mon	24	—	unknown	03:40–05:25 (marginal, 1.75 h)	72.6° 00:25	10.98	100%	5.2°
2043-11-17 Tue	26	—	unknown	19:25–21:55 (marginal, 2.5 h)	72.5° 00:25	11.01	98%	10.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-10-19&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.