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: 10-16 (100), 10-17 (100), 10-18 (100), 10-19 (100), 10-20 (100) — by astronomy; check the weather when the night is within four days.

2042-10-16astronomy score per night — click a bar for that night2042-11-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-10-16 Thu	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.2° 01:15	9.87	7%	153.8°
2042-10-17 Fri	100	—	unknown	20:10–06:05 (good, 9.92 h)	79.2° 01:10	9.91	13%	144.2°
2042-10-18 Sat	100	—	unknown	20:10–06:05 (good, 9.92 h)	79.2° 01:05	9.95	20%	133.6°
2042-10-19 Sun	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.2° 01:05	10.0	28%	122.3°
2042-10-20 Mon	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.2° 01:00	10.04	38%	110.5°
2042-10-21 Tue	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.2° 00:55	10.08	48%	98.3°
2042-10-22 Wed	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.2° 00:50	10.12	58%	85.8°
2042-10-23 Thu	100	—	unknown	20:05–06:15 (good, 10.17 h)	79.2° 00:50	10.16	69%	72.8°
2042-10-24 Fri	99	—	unknown	21:40–06:15 (good, 8.58 h)	79.2° 00:45	10.2	79%	59.6°
2042-10-25 Sat	89	—	unknown	02:30–05:10 (good, 3.67 h)	79.2° 00:40	10.24	88%	46.2°
2042-10-26 Sun	75	—	unknown	04:45–05:10 (good, 0.42 h)	79.2° 23:35	10.28	94%	33.2°
2042-10-27 Mon	35	—	unknown	00:55–05:10 (marginal, 4.25 h)	79.2° 23:30	10.32	99%	22.1°
2042-10-28 Tue	31	—	unknown	18:55–21:40 (marginal, 2.75 h)	79.2° 23:30	10.36	100%	18.0°
2042-10-29 Wed	35	—	unknown	18:55–22:30 (marginal, 3.58 h)	79.2° 23:25	10.4	98%	24.7°
2042-10-30 Thu	52	—	unknown	18:55–02:05 (marginal, 7.17 h)	79.2° 23:20	10.43	93%	36.4°
2042-10-31 Fri	86	—	unknown	18:55–21:35 (good, 2.67 h)	79.2° 23:15	10.47	86%	49.4°
2042-11-01 Sat	93	—	unknown	18:50–01:25 (good, 6.58 h)	79.2° 23:10	10.51	78%	62.5°
2042-11-02 Sun	100	—	unknown	18:50–03:20 (good, 8.5 h)	79.2° 23:10	10.54	68%	75.4°
2042-11-03 Mon	100	—	unknown	18:50–04:15 (good, 9.42 h)	79.2° 23:05	10.58	58%	87.9°
2042-11-04 Tue	100	—	unknown	18:50–04:20 (good, 9.5 h)	79.2° 23:00	10.61	47%	100.1°
2042-11-05 Wed	100	—	unknown	18:50–04:25 (good, 9.58 h)	79.2° 22:55	10.65	38%	111.9°
2042-11-06 Thu	100	—	unknown	18:45–04:20 (good, 9.58 h)	79.2° 22:50	10.68	28%	123.3°
2042-11-07 Fri	100	—	unknown	18:45–04:20 (good, 9.58 h)	79.2° 22:50	10.71	20%	134.3°
2042-11-08 Sat	100	—	unknown	18:45–04:15 (good, 9.5 h)	79.2° 22:45	10.75	13%	144.8°
2042-11-09 Sun	100	—	unknown	18:45–04:15 (good, 9.5 h)	79.2° 22:40	10.78	8%	154.1°
2042-11-10 Mon	100	—	unknown	18:45–04:10 (good, 9.42 h)	79.2° 22:35	10.81	3%	160.7°
2042-11-11 Tue	100	—	unknown	18:45–04:05 (good, 9.33 h)	79.2° 22:35	10.84	1%	161.5°
2042-11-12 Wed	100	—	unknown	18:40–04:00 (good, 9.33 h)	79.2° 22:30	10.87	0%	155.8°
2042-11-13 Thu	100	—	unknown	18:40–03:55 (good, 9.25 h)	79.2° 22:25	10.9	1%	146.7°
2042-11-14 Fri	100	—	unknown	18:40–03:55 (good, 9.25 h)	79.2° 22:20	10.93	4%	136.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-10-16&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.