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: 08-14 (100), 08-15 (100), 08-16 (100), 08-17 (100), 08-18 (100) — by astronomy; check the weather when the night is within four days.

2031-08-14astronomy score per night — click a bar for that night2031-09-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-08-14 Thu	100	—	unknown	23:55–04:45 (good, 4.83 h)	79.1° 05:25	6.57	10%	75.3°
2031-08-15 Fri	100	—	unknown	23:50–04:45 (good, 4.92 h)	79.1° 05:20	6.63	5%	86.6°
2031-08-16 Sat	100	—	unknown	23:50–04:50 (good, 5.0 h)	79.1° 05:15	6.69	2%	97.9°
2031-08-17 Sun	100	—	unknown	23:45–04:50 (good, 5.08 h)	79.1° 05:10	6.75	0%	109.3°
2031-08-18 Mon	100	—	unknown	23:40–04:50 (good, 5.17 h)	79.1° 05:10	6.8	1%	120.7°
2031-08-19 Tue	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.1° 05:05	6.86	3%	132.1°
2031-08-20 Wed	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.1° 05:00	6.92	7%	143.2°
2031-08-21 Thu	100	—	unknown	23:30–04:55 (good, 5.42 h)	79.1° 04:55	6.98	14%	153.5°
2031-08-22 Fri	100	—	unknown	23:25–05:00 (good, 5.58 h)	79.1° 04:50	7.03	21%	161.0°
2031-08-23 Sat	100	—	unknown	23:20–05:00 (good, 5.67 h)	79.1° 04:50	7.09	30%	161.4°
2031-08-24 Sun	100	—	unknown	23:15–05:00 (good, 5.75 h)	79.1° 04:45	7.15	41%	154.1°
2031-08-25 Mon	100	—	unknown	23:15–05:00 (good, 5.75 h)	79.1° 04:40	7.2	52%	143.1°
2031-08-26 Tue	100	—	unknown	23:15–05:05 (good, 5.83 h)	79.1° 04:35	7.26	63%	130.6°
2031-08-27 Wed	100	—	unknown	23:15–05:05 (good, 5.83 h)	79.1° 04:30	7.32	74%	117.3°
2031-08-28 Thu	100	—	unknown	23:20–05:05 (good, 5.75 h)	79.1° 04:30	7.37	83%	103.5°
2031-08-29 Fri	100	—	unknown	23:35–05:10 (good, 5.58 h)	79.1° 04:25	7.43	91%	89.4°
2031-08-30 Sat	76	—	unknown	01:15–05:10 (good, 3.92 h)	79.1° 04:20	7.49	97%	75.3°
2031-08-31 Sun	58	—	unknown	04:20–05:10 (good, 0.83 h)	79.1° 04:15	7.54	100%	61.3°
2031-09-01 Mon	38	—	unknown	22:45–05:10 (marginal, 6.42 h)	79.1° 04:15	7.6	99%	47.7°
2031-09-02 Tue	25	—	unknown	22:50–05:15 (marginal, 6.42 h)	79.1° 04:10	7.66	97%	35.0°
2031-09-03 Wed	25	—	unknown	22:35–05:15 (marginal, 6.67 h)	79.1° 04:05	7.71	92%	24.1°
2031-09-04 Thu	34	—	unknown	22:20–05:15 (marginal, 6.92 h)	79.1° 04:00	7.77	84%	18.0°
2031-09-05 Fri	45	—	unknown	22:05–05:15 (marginal, 7.17 h)	79.1° 03:55	7.82	76%	20.3°
2031-09-06 Sat	68	—	unknown	22:25–22:40 (good, 0.25 h)	79.1° 03:55	7.88	67%	28.6°
2031-09-07 Sun	84	—	unknown	22:20–05:20 (good, 7.0 h)	79.1° 03:50	7.93	57%	38.9°
2031-09-08 Mon	90	—	unknown	22:20–05:20 (good, 7.0 h)	79.1° 03:45	7.99	48%	49.8°
2031-09-09 Tue	97	—	unknown	22:15–05:20 (good, 7.08 h)	79.1° 03:40	8.04	38%	60.9°
2031-09-10 Wed	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.1° 03:35	8.09	29%	72.0°
2031-09-11 Thu	100	—	unknown	22:05–05:25 (good, 7.33 h)	79.1° 03:35	8.15	21%	83.3°
2031-09-12 Fri	100	—	unknown	22:00–05:25 (good, 7.42 h)	79.1° 03:30	8.2	14%	94.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-08-14&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.