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: 09-13 (100), 09-14 (100), 09-15 (100), 09-16 (100), 09-17 (100) — by astronomy; check the weather when the night is within four days.

2029-09-13astronomy score per night — click a bar for that night2029-10-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-09-13 Thu	100	—	unknown	22:00–05:30 (good, 7.5 h)	79.1° 03:25	8.28	37%	142.9°
2029-09-14 Fri	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.1° 03:20	8.33	48%	130.0°
2029-09-15 Sat	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.1° 03:15	8.39	60%	117.1°
2029-09-16 Sun	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.1° 03:10	8.44	70%	104.3°
2029-09-17 Mon	100	—	unknown	22:05–05:35 (good, 7.5 h)	79.1° 03:10	8.49	79%	91.7°
2029-09-18 Tue	100	—	unknown	22:50–05:35 (good, 6.75 h)	79.1° 03:05	8.54	86%	79.3°
2029-09-19 Wed	100	—	unknown	00:30–05:35 (good, 5.08 h)	79.1° 03:00	8.59	93%	67.2°
2029-09-20 Thu	67	—	unknown	03:55–05:35 (good, 1.67 h)	79.1° 02:55	8.65	97%	55.4°
2029-09-21 Fri	53	—	unknown	21:30–05:40 (marginal, 8.17 h)	79.1° 02:50	8.7	99%	43.9°
2029-09-22 Sat	33	—	unknown	01:45–05:40 (marginal, 3.92 h)	79.1° 02:50	8.75	100%	32.9°
2029-09-23 Sun	26	—	unknown	21:25–00:00 (marginal, 2.58 h)	79.1° 02:45	8.8	98%	23.1°
2029-09-24 Mon	29	—	unknown	21:10–01:15 (marginal, 4.08 h)	79.1° 02:40	8.85	95%	16.2°
2029-09-25 Tue	36	—	unknown	20:55–05:40 (marginal, 8.75 h)	79.1° 02:35	8.9	91%	16.4°
2029-09-26 Wed	47	—	unknown	20:45–05:45 (marginal, 9.0 h)	79.1° 02:30	8.95	84%	23.4°
2029-09-27 Thu	75	—	unknown	21:00–21:25 (good, 0.42 h)	79.1° 02:30	9.0	77%	33.1°
2029-09-28 Fri	85	—	unknown	20:55–02:10 (good, 5.25 h)	79.1° 02:25	9.05	69%	44.0°
2029-09-29 Sat	92	—	unknown	20:55–05:40 (good, 8.75 h)	79.1° 02:20	9.1	59%	55.4°
2029-09-30 Sun	100	—	unknown	20:50–05:50 (good, 9.0 h)	79.1° 02:15	9.14	50%	67.2°
2029-10-01 Mon	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.1° 02:15	9.19	39%	79.4°
2029-10-02 Tue	100	—	unknown	20:40–05:50 (good, 9.17 h)	79.1° 02:10	9.24	29%	92.0°
2029-10-03 Wed	100	—	unknown	20:40–05:50 (good, 9.17 h)	79.1° 02:05	9.29	20%	105.1°
2029-10-04 Thu	100	—	unknown	20:35–05:50 (good, 9.25 h)	79.1° 02:00	9.34	12%	118.6°
2029-10-05 Fri	100	—	unknown	20:30–05:55 (good, 9.42 h)	79.1° 01:55	9.38	5%	132.3°
2029-10-06 Sat	100	—	unknown	20:30–05:55 (good, 9.42 h)	79.1° 01:55	9.43	1%	145.9°
2029-10-07 Sun	100	—	unknown	20:25–05:55 (good, 9.5 h)	79.1° 01:50	9.48	0%	158.2°
2029-10-08 Mon	100	—	unknown	20:25–05:55 (good, 9.5 h)	79.1° 01:45	9.52	2%	164.8°
2029-10-09 Tue	100	—	unknown	20:25–06:00 (good, 9.58 h)	79.1° 01:40	9.57	7%	159.1°
2029-10-10 Wed	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:35	9.61	14%	147.2°
2029-10-11 Thu	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:35	9.66	23%	133.9°
2029-10-12 Fri	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:30	9.7	33%	120.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-09-13&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.