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: 10-07 (100), 10-08 (100), 10-09 (100), 10-10 (100), 10-11 (100) — by astronomy; check the weather when the night is within four days.

2031-09-30astronomy score per night — click a bar for that night2031-10-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-09-30 Tue	31	—	unknown	02:55–05:45 (marginal, 2.83 h)	79.1° 02:20	9.12	100%	28.4°
2031-10-01 Wed	28	—	unknown	20:50–00:15 (marginal, 3.42 h)	79.1° 02:15	9.17	98%	19.7°
2031-10-02 Thu	35	—	unknown	20:35–01:40 (marginal, 5.08 h)	79.1° 02:10	9.22	95%	18.5°
2031-10-03 Fri	46	—	unknown	20:35–05:50 (marginal, 9.25 h)	79.1° 02:05	9.27	89%	25.1°
2031-10-04 Sat	81	—	unknown	20:35–21:15 (good, 0.67 h)	79.1° 02:05	9.31	82%	35.1°
2031-10-05 Sun	88	—	unknown	20:30–01:25 (good, 4.92 h)	79.1° 02:00	9.36	73%	46.0°
2031-10-06 Mon	94	—	unknown	20:30–04:55 (good, 8.42 h)	79.1° 01:55	9.41	64%	57.1°
2031-10-07 Tue	100	—	unknown	20:30–05:55 (good, 9.42 h)	79.1° 01:50	9.45	55%	68.4°
2031-10-08 Wed	100	—	unknown	20:25–05:55 (good, 9.5 h)	79.1° 01:45	9.5	46%	79.6°
2031-10-09 Thu	100	—	unknown	20:25–05:55 (good, 9.5 h)	79.1° 01:45	9.54	36%	90.9°
2031-10-10 Fri	100	—	unknown	20:25–06:00 (good, 9.58 h)	79.1° 01:40	9.59	27%	102.2°
2031-10-11 Sat	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:35	9.64	19%	113.6°
2031-10-12 Sun	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:30	9.68	12%	125.0°
2031-10-13 Mon	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:30	9.72	6%	136.5°
2031-10-14 Tue	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:25	9.77	2%	147.5°
2031-10-15 Wed	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:20	9.81	0%	157.1°
2031-10-16 Thu	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:15	9.86	0%	162.1°
2031-10-17 Fri	100	—	unknown	20:10–06:05 (good, 9.92 h)	79.1° 01:10	9.9	3%	158.3°
2031-10-18 Sat	100	—	unknown	20:10–06:05 (good, 9.92 h)	79.1° 01:10	9.94	8%	148.6°
2031-10-19 Sun	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.1° 01:05	9.98	15%	136.6°
2031-10-20 Mon	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.1° 01:00	10.02	24%	123.7°
2031-10-21 Tue	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.1° 00:55	10.07	34%	110.4°
2031-10-22 Wed	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.1° 00:50	10.11	46%	97.0°
2031-10-23 Thu	100	—	unknown	20:05–06:15 (good, 10.17 h)	79.1° 00:50	10.15	57%	83.6°
2031-10-24 Fri	100	—	unknown	20:15–06:15 (good, 10.0 h)	79.1° 00:45	10.19	68%	70.2°
2031-10-25 Sat	98	—	unknown	22:15–05:15 (good, 8.0 h)	79.1° 00:40	10.23	78%	57.0°
2031-10-26 Sun	89	—	unknown	01:40–05:10 (good, 3.5 h)	79.1° 23:35	10.27	87%	44.2°
2031-10-27 Mon	79	—	unknown	04:35–05:05 (good, 0.5 h)	79.1° 23:35	10.31	93%	32.2°
2031-10-28 Tue	38	—	unknown	00:25–05:10 (marginal, 4.75 h)	79.1° 23:30	10.34	98%	22.3°
2031-10-29 Wed	30	—	unknown	18:55–21:30 (marginal, 2.58 h)	79.1° 23:25	10.38	100%	17.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-09-30&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.