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: 09-18 (100), 09-19 (100), 09-20 (100), 09-21 (100), 09-22 (100) — by astronomy; check the weather when the night is within four days.

2036-09-18astronomy score per night — click a bar for that night2036-10-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-09-18 Thu	100	—	unknown	21:35–05:35 (good, 8.0 h)	79.1° 03:05	8.56	2%	124.0°
2036-09-19 Fri	100	—	unknown	21:30–05:35 (good, 8.08 h)	79.2° 03:00	8.61	0%	136.5°
2036-09-20 Sat	100	—	unknown	21:30–05:35 (good, 8.08 h)	79.2° 02:55	8.66	1%	147.3°
2036-09-21 Sun	100	—	unknown	21:25–05:40 (good, 8.25 h)	79.2° 02:50	8.71	5%	154.4°
2036-09-22 Mon	100	—	unknown	21:20–05:40 (good, 8.33 h)	79.1° 02:45	8.76	11%	154.9°
2036-09-23 Tue	100	—	unknown	21:15–05:40 (good, 8.42 h)	79.1° 02:45	8.81	19%	149.1°
2036-09-24 Wed	100	—	unknown	21:15–05:40 (good, 8.42 h)	79.2° 02:40	8.86	27%	140.1°
2036-09-25 Thu	100	—	unknown	21:10–05:45 (good, 8.58 h)	79.2° 02:35	8.91	37%	129.8°
2036-09-26 Fri	100	—	unknown	21:10–05:45 (good, 8.58 h)	79.1° 02:30	8.96	47%	119.1°
2036-09-27 Sat	100	—	unknown	21:10–05:45 (good, 8.58 h)	79.1° 02:30	9.01	56%	108.3°
2036-09-28 Sun	100	—	unknown	21:10–05:45 (good, 8.58 h)	79.2° 02:25	9.06	66%	97.4°
2036-09-29 Mon	100	—	unknown	21:15–05:45 (good, 8.5 h)	79.2° 02:20	9.11	74%	86.7°
2036-09-30 Tue	100	—	unknown	22:00–05:50 (good, 7.83 h)	79.2° 02:15	9.16	82%	75.9°
2036-10-01 Wed	100	—	unknown	23:30–05:50 (good, 6.33 h)	79.1° 02:10	9.21	89%	65.2°
2036-10-02 Thu	95	—	unknown	02:55–05:50 (good, 2.92 h)	79.1° 02:10	9.25	94%	54.7°
2036-10-03 Fri	58	—	unknown	20:35–05:50 (marginal, 9.25 h)	79.2° 02:05	9.3	98%	44.5°
2036-10-04 Sat	46	—	unknown	20:30–05:55 (marginal, 9.42 h)	79.2° 02:00	9.35	100%	35.2°
2036-10-05 Sun	33	—	unknown	20:30–00:50 (marginal, 4.33 h)	79.2° 01:55	9.4	100%	27.7°
2036-10-06 Mon	37	—	unknown	20:30–01:25 (marginal, 4.92 h)	79.1° 01:50	9.44	98%	24.3°
2036-10-07 Tue	45	—	unknown	20:20–05:55 (marginal, 9.58 h)	79.1° 01:50	9.49	93%	26.9°
2036-10-08 Wed	81	—	unknown	20:25–21:00 (good, 0.58 h)	79.2° 01:45	9.53	87%	34.3°
2036-10-09 Thu	87	—	unknown	20:25–00:10 (good, 3.75 h)	79.2° 01:40	9.58	79%	44.3°
2036-10-10 Fri	94	—	unknown	20:20–04:00 (good, 7.67 h)	79.2° 01:35	9.63	70%	55.7°
2036-10-11 Sat	100	—	unknown	20:20–05:50 (good, 9.5 h)	79.1° 01:35	9.67	59%	67.8°
2036-10-12 Sun	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.2° 01:30	9.71	48%	80.4°
2036-10-13 Mon	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.2° 01:25	9.76	37%	93.2°
2036-10-14 Tue	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.2° 01:20	9.8	26%	106.2°
2036-10-15 Wed	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:15	9.85	17%	119.1°
2036-10-16 Thu	100	—	unknown	20:10–06:05 (good, 9.92 h)	79.1° 01:15	9.89	9%	131.7°
2036-10-17 Fri	100	—	unknown	20:10–06:05 (good, 9.92 h)	79.2° 01:10	9.93	3%	143.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-09-18&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.