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: 09-05 (100), 09-06 (100), 09-07 (100), 09-08 (100), 09-09 (100) — by astronomy; check the weather when the night is within four days.

2046-09-05astronomy score per night — click a bar for that night2046-10-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-09-05 Wed	100	—	unknown	22:30–05:20 (good, 6.83 h)	79.2° 03:55	7.84	34%	154.2°
2046-09-06 Thu	100	—	unknown	22:30–05:20 (good, 6.83 h)	79.2° 03:50	7.9	45%	142.1°
2046-09-07 Fri	100	—	unknown	22:25–05:20 (good, 6.92 h)	79.2° 03:50	7.95	56%	129.6°
2046-09-08 Sat	100	—	unknown	22:25–05:20 (good, 6.92 h)	79.2° 03:45	8.01	66%	117.2°
2046-09-09 Sun	100	—	unknown	22:25–05:25 (good, 7.0 h)	79.2° 03:40	8.06	75%	104.9°
2046-09-10 Mon	100	—	unknown	22:30–05:25 (good, 6.92 h)	79.2° 03:35	8.11	83%	92.9°
2046-09-11 Tue	100	—	unknown	23:15–05:25 (good, 6.17 h)	79.2° 03:35	8.17	90%	81.0°
2046-09-12 Wed	100	—	unknown	00:50–05:25 (good, 4.58 h)	79.2° 03:30	8.22	95%	69.3°
2046-09-13 Thu	67	—	unknown	04:00–05:30 (good, 1.5 h)	79.2° 03:25	8.27	98%	57.7°
2046-09-14 Fri	50	—	unknown	21:55–05:30 (marginal, 7.58 h)	79.2° 03:20	8.33	100%	46.4°
2046-09-15 Sat	33	—	unknown	22:00–05:30 (marginal, 7.5 h)	79.2° 03:15	8.38	100%	35.5°
2046-09-16 Sun	25	—	unknown	21:55–01:00 (marginal, 3.08 h)	79.2° 03:15	8.43	97%	25.2°
2046-09-17 Mon	27	—	unknown	21:40–02:15 (marginal, 4.58 h)	79.2° 03:10	8.49	94%	16.9°
2046-09-18 Tue	35	—	unknown	21:25–05:35 (marginal, 8.17 h)	79.2° 03:05	8.54	88%	14.5°
2046-09-19 Wed	46	—	unknown	21:15–05:35 (marginal, 8.33 h)	79.2° 03:00	8.59	82%	20.4°
2046-09-20 Thu	62	—	unknown	21:30–21:35 (good, 0.08 h)	79.2° 02:55	8.64	73%	30.2°
2046-09-21 Fri	83	—	unknown	21:25–02:50 (good, 5.42 h)	79.2° 02:55	8.69	64%	41.3°
2046-09-22 Sat	89	—	unknown	21:20–05:40 (good, 8.33 h)	79.2° 02:50	8.74	54%	53.2°
2046-09-23 Sun	97	—	unknown	21:20–05:40 (good, 8.33 h)	79.2° 02:45	8.79	44%	65.6°
2046-09-24 Mon	100	—	unknown	21:15–05:40 (good, 8.42 h)	79.2° 02:40	8.84	33%	78.5°
2046-09-25 Tue	100	—	unknown	21:10–05:40 (good, 8.5 h)	79.2° 02:40	8.89	23%	91.9°
2046-09-26 Wed	100	—	unknown	21:05–05:45 (good, 8.67 h)	79.2° 02:35	8.94	14%	105.7°
2046-09-27 Thu	100	—	unknown	21:00–05:45 (good, 8.75 h)	79.2° 02:30	8.99	7%	119.9°
2046-09-28 Fri	100	—	unknown	21:00–05:45 (good, 8.75 h)	79.2° 02:25	9.04	2%	134.2°
2046-09-29 Sat	100	—	unknown	20:55–05:45 (good, 8.83 h)	79.2° 02:20	9.09	0%	148.2°
2046-09-30 Sun	100	—	unknown	20:50–05:50 (good, 9.0 h)	79.2° 02:20	9.14	1%	160.4°
2046-10-01 Mon	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.2° 02:15	9.19	5%	165.6°
2046-10-02 Tue	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.2° 02:10	9.24	12%	158.3°
2046-10-03 Wed	100	—	unknown	20:40–05:50 (good, 9.17 h)	79.2° 02:05	9.28	20%	146.3°
2046-10-04 Thu	100	—	unknown	20:35–05:50 (good, 9.25 h)	79.2° 02:00	9.33	30%	133.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-09-05&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.