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 Triangulum Pinwheel: 10-09 (100), 10-10 (100), 10-11 (100), 10-12 (100), 10-13 (100) — by astronomy; check the weather when the night is within four days.

2039-10-09astronomy score per night — click a bar for that night2039-11-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-10-09 Sun	100	—	unknown	20:25–05:55 (good, 9.5 h)	79.2° 01:45	9.55	54%	68.8°
2039-10-10 Mon	100	—	unknown	20:25–06:00 (good, 9.58 h)	79.2° 01:40	9.59	45%	79.7°
2039-10-11 Tue	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.2° 01:35	9.64	35%	90.9°
2039-10-12 Wed	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.2° 01:30	9.68	26%	102.4°
2039-10-13 Thu	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.2° 01:30	9.73	18%	114.1°
2039-10-14 Fri	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.2° 01:25	9.77	10%	125.8°
2039-10-15 Sat	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.2° 01:20	9.81	5%	137.4°
2039-10-16 Sun	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.2° 01:15	9.86	1%	148.1°
2039-10-17 Mon	100	—	unknown	20:10–06:05 (good, 9.92 h)	79.2° 01:10	9.9	0%	155.7°
2039-10-18 Tue	100	—	unknown	20:10–06:05 (good, 9.92 h)	79.2° 01:10	9.94	2%	156.6°
2039-10-19 Wed	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.2° 01:05	9.99	6%	149.9°
2039-10-20 Thu	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.2° 01:00	10.03	13%	139.0°
2039-10-21 Fri	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.2° 00:55	10.07	22%	126.6°
2039-10-22 Sat	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.2° 00:50	10.11	32%	113.8°
2039-10-23 Sun	100	—	unknown	20:05–06:15 (good, 10.17 h)	79.2° 00:50	10.15	44%	100.8°
2039-10-24 Mon	100	—	unknown	20:00–06:15 (good, 10.25 h)	79.2° 00:45	10.19	55%	88.0°
2039-10-25 Tue	100	—	unknown	20:00–06:15 (good, 10.25 h)	79.2° 00:40	10.23	66%	75.4°
2039-10-26 Wed	100	—	unknown	20:50–06:10 (good, 9.33 h)	79.2° 00:35	10.27	75%	63.2°
2039-10-27 Thu	93	—	unknown	00:40–06:05 (good, 5.42 h)	79.2° 00:35	10.31	84%	51.5°
2039-10-28 Fri	84	—	unknown	04:55–06:00 (good, 1.08 h)	79.2° 00:30	10.35	91%	40.5°
2039-10-29 Sat	60	—	unknown	19:55–05:20 (marginal, 10.42 h)	79.2° 00:25	10.38	96%	31.0°
2039-10-30 Sun	35	—	unknown	00:45–05:00 (marginal, 4.25 h)	79.2° 23:20	10.42	99%	24.4°
2039-10-31 Mon	34	—	unknown	18:55–22:05 (marginal, 3.17 h)	79.2° 23:15	10.46	100%	22.9°
2039-11-01 Tue	37	—	unknown	18:50–22:35 (marginal, 3.75 h)	79.2° 23:15	10.5	99%	27.2°
2039-11-02 Wed	48	—	unknown	18:50–00:40 (marginal, 5.83 h)	79.2° 23:10	10.53	96%	35.1°
2039-11-03 Thu	86	—	unknown	18:50–18:55 (good, 0.08 h)	79.2° 23:05	10.57	92%	44.5°
2039-11-04 Fri	90	—	unknown	18:50–22:25 (good, 3.58 h)	79.2° 23:00	10.6	86%	54.8°
2039-11-05 Sat	97	—	unknown	18:50–01:30 (good, 6.67 h)	79.2° 22:55	10.64	79%	65.3°
2039-11-06 Sun	100	—	unknown	18:45–02:55 (good, 8.17 h)	79.2° 22:55	10.67	71%	76.1°
2039-11-07 Mon	100	—	unknown	18:45–03:55 (good, 9.17 h)	79.2° 22:50	10.71	62%	87.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-10-09&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.