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: 08-17 (100), 08-18 (100), 08-19 (100), 08-20 (100), 08-01 (95) — by astronomy; check the weather when the night is within four days.

2047-07-22astronomy score per night — click a bar for that night2047-08-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-07-22 Mon	73	—	unknown	01:25–04:10 (good, 2.75 h)	79.2° 06:55	5.32	0%	87.2°
2047-07-23 Tue	75	—	unknown	01:25–04:10 (good, 2.75 h)	79.2° 06:50	5.37	1%	100.2°
2047-07-24 Wed	79	—	unknown	01:20–04:15 (good, 2.92 h)	79.2° 06:45	5.42	5%	113.3°
2047-07-25 Thu	82	—	unknown	01:15–04:15 (good, 3.0 h)	79.2° 06:40	5.47	10%	126.5°
2047-07-26 Fri	84	—	unknown	01:10–04:15 (good, 3.08 h)	79.2° 06:40	5.52	18%	139.6°
2047-07-27 Sat	87	—	unknown	01:05–04:20 (good, 3.25 h)	79.2° 06:35	5.57	28%	152.1°
2047-07-28 Sun	89	—	unknown	01:05–04:20 (good, 3.25 h)	79.2° 06:30	5.63	39%	162.5°
2047-07-29 Mon	91	—	unknown	01:00–04:20 (good, 3.33 h)	79.2° 06:25	5.68	50%	165.1°
2047-07-30 Tue	93	—	unknown	00:55–04:20 (good, 3.42 h)	79.2° 06:25	5.73	62%	156.9°
2047-07-31 Wed	94	—	unknown	00:55–04:25 (good, 3.5 h)	79.2° 06:20	5.79	72%	144.8°
2047-08-01 Thu	95	—	unknown	00:55–04:25 (good, 3.5 h)	79.2° 06:15	5.84	82%	131.7°
2047-08-02 Fri	94	—	unknown	00:55–04:25 (good, 3.5 h)	79.2° 06:10	5.9	90%	118.3°
2047-08-03 Sat	88	—	unknown	01:00–04:30 (good, 3.5 h)	79.2° 06:05	5.95	96%	105.0°
2047-08-04 Sun	63	—	unknown	01:15–04:30 (good, 3.25 h)	79.2° 06:05	6.01	99%	91.7°
2047-08-05 Mon	49	—	unknown	02:35–04:30 (good, 1.92 h)	79.2° 06:00	6.07	100%	78.7°
2047-08-06 Tue	38	—	unknown	00:15–04:35 (marginal, 4.33 h)	79.2° 05:55	6.12	99%	65.9°
2047-08-07 Wed	28	—	unknown	00:15–04:35 (marginal, 4.33 h)	79.2° 05:50	6.18	95%	53.6°
2047-08-08 Thu	23	—	unknown	00:15–04:35 (marginal, 4.33 h)	79.2° 05:45	6.24	90%	41.8°
2047-08-09 Fri	21	—	unknown	00:10–04:40 (marginal, 4.5 h)	79.2° 05:45	6.29	83%	30.6°
2047-08-10 Sat	27	—	unknown	23:55–04:40 (marginal, 4.75 h)	79.2° 05:40	6.35	75%	20.8°
2047-08-11 Sun	36	—	unknown	23:45–04:40 (marginal, 4.92 h)	79.2° 05:35	6.41	67%	14.8°
2047-08-12 Mon	49	—	unknown	02:10–03:45 (good, 1.58 h)	79.2° 05:30	6.47	57%	16.7°
2047-08-13 Tue	63	—	unknown	00:25–04:45 (good, 4.33 h)	79.2° 05:30	6.52	48%	24.8°
2047-08-14 Wed	80	—	unknown	23:55–04:45 (good, 4.83 h)	79.2° 05:25	6.58	39%	35.1°
2047-08-15 Thu	87	—	unknown	23:50–04:45 (good, 4.92 h)	79.2° 05:20	6.64	30%	46.3°
2047-08-16 Fri	94	—	unknown	23:50–04:50 (good, 5.0 h)	79.2° 05:15	6.7	21%	57.9°
2047-08-17 Sat	100	—	unknown	23:45–04:50 (good, 5.08 h)	79.2° 05:10	6.75	13%	70.1°
2047-08-18 Sun	100	—	unknown	23:40–04:50 (good, 5.17 h)	79.2° 05:10	6.81	7%	82.6°
2047-08-19 Mon	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 05:05	6.87	3%	95.5°
2047-08-20 Tue	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 05:00	6.93	0%	108.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-07-22&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.