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: 08-27 (100), 08-28 (100), 08-29 (100), 08-30 (100), 08-31 (100) — by astronomy; check the weather when the night is within four days.

2046-08-20astronomy score per night — click a bar for that night2046-09-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-08-20 Mon	25	—	unknown	23:25–04:55 (marginal, 5.5 h)	79.2° 05:00	6.94	84%	22.6°
2046-08-21 Tue	33	—	unknown	23:10–04:55 (marginal, 5.75 h)	79.2° 04:55	7.0	76%	15.3°
2046-08-22 Wed	44	—	unknown	23:00–05:00 (marginal, 6.0 h)	79.2° 04:50	7.05	68%	15.3°
2046-08-23 Thu	59	—	unknown	00:30–03:15 (good, 2.75 h)	79.2° 04:45	7.11	58%	22.8°
2046-08-24 Fri	72	—	unknown	23:15–05:00 (good, 5.75 h)	79.2° 04:45	7.17	48%	33.2°
2046-08-25 Sat	85	—	unknown	23:10–05:05 (good, 5.92 h)	79.2° 04:40	7.23	38%	44.9°
2046-08-26 Sun	92	—	unknown	23:10–05:05 (good, 5.92 h)	79.2° 04:35	7.28	28%	57.2°
2046-08-27 Mon	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.2° 04:30	7.34	19%	70.2°
2046-08-28 Tue	100	—	unknown	23:00–05:05 (good, 6.08 h)	79.2° 04:30	7.4	11%	83.7°
2046-08-29 Wed	100	—	unknown	22:55–05:10 (good, 6.25 h)	79.2° 04:25	7.45	5%	97.7°
2046-08-30 Thu	100	—	unknown	22:50–05:10 (good, 6.33 h)	79.2° 04:20	7.51	1%	112.0°
2046-08-31 Fri	100	—	unknown	22:50–05:10 (good, 6.33 h)	79.2° 04:15	7.56	0%	126.5°
2046-09-01 Sat	100	—	unknown	22:45–05:10 (good, 6.42 h)	79.2° 04:10	7.62	2%	140.7°
2046-09-02 Sun	100	—	unknown	22:40–05:15 (good, 6.58 h)	79.2° 04:10	7.68	7%	154.1°
2046-09-03 Mon	100	—	unknown	22:35–05:15 (good, 6.67 h)	79.2° 04:05	7.73	15%	164.2°
2046-09-04 Tue	100	—	unknown	22:35–05:15 (good, 6.67 h)	79.2° 04:00	7.79	24%	163.9°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-08-20&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.