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: 08-18 (100), 08-19 (100), 08-20 (100), 08-21 (100), 08-22 (100) — by astronomy; check the weather when the night is within four days.

2036-08-12astronomy score per night — click a bar for that night2036-09-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-08-12 Tue	37	—	unknown	23:35–04:45 (marginal, 5.17 h)	79.1° 05:30	6.5	71%	25.5°
2036-08-13 Wed	49	—	unknown	02:05–03:25 (good, 1.33 h)	79.2° 05:25	6.56	62%	25.1°
2036-08-14 Thu	76	—	unknown	23:55–04:45 (good, 4.83 h)	79.2° 05:20	6.62	51%	30.3°
2036-08-15 Fri	85	—	unknown	23:50–04:50 (good, 5.0 h)	79.1° 05:15	6.68	41%	39.3°
2036-08-16 Sat	92	—	unknown	23:45–04:50 (good, 5.08 h)	79.1° 05:15	6.73	30%	50.4°
2036-08-17 Sun	98	—	unknown	23:40–04:50 (good, 5.17 h)	79.2° 05:10	6.79	20%	62.7°
2036-08-18 Mon	100	—	unknown	23:40–04:55 (good, 5.25 h)	79.2° 05:05	6.85	11%	75.8°
2036-08-19 Tue	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 05:00	6.91	5%	89.3°
2036-08-20 Wed	100	—	unknown	23:30–04:55 (good, 5.42 h)	79.1° 04:55	6.96	1%	103.1°
2036-08-21 Thu	100	—	unknown	23:25–04:55 (good, 5.5 h)	79.1° 04:55	7.02	0%	116.7°
2036-08-22 Fri	100	—	unknown	23:20–05:00 (good, 5.67 h)	79.2° 04:50	7.08	2%	129.8°
2036-08-23 Sat	100	—	unknown	23:20–05:00 (good, 5.67 h)	79.2° 04:45	7.13	7%	141.6°
2036-08-24 Sun	100	—	unknown	23:15–05:00 (good, 5.75 h)	79.2° 04:40	7.19	14%	151.0°
2036-08-25 Mon	100	—	unknown	23:10–05:05 (good, 5.92 h)	79.1° 04:35	7.25	23%	155.4°
2036-08-26 Tue	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.1° 04:35	7.31	33%	153.1°
2036-08-27 Wed	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.2° 04:30	7.36	43%	146.0°
2036-08-28 Thu	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.2° 04:25	7.42	53%	136.6°
2036-08-29 Fri	100	—	unknown	23:00–05:10 (good, 6.17 h)	79.1° 04:20	7.48	63%	126.3°
2036-08-30 Sat	100	—	unknown	23:00–05:10 (good, 6.17 h)	79.1° 04:20	7.53	72%	115.7°
2036-08-31 Sun	100	—	unknown	23:00–05:10 (good, 6.17 h)	79.2° 04:15	7.59	80%	105.0°
2036-09-01 Mon	100	—	unknown	23:05–05:15 (good, 6.17 h)	79.2° 04:10	7.64	87%	94.2°
2036-09-02 Tue	100	—	unknown	23:45–05:15 (good, 5.5 h)	79.2° 04:05	7.7	93%	83.5°
2036-09-03 Wed	76	—	unknown	01:00–05:15 (good, 4.25 h)	79.1° 04:00	7.75	97%	72.7°
2036-09-04 Thu	67	—	unknown	03:35–05:15 (good, 1.67 h)	79.1° 04:00	7.81	99%	62.1°
2036-09-05 Fri	51	—	unknown	22:20–05:20 (marginal, 7.0 h)	79.2° 03:55	7.86	100%	51.7°
2036-09-06 Sat	38	—	unknown	22:20–05:20 (marginal, 7.0 h)	79.2° 03:50	7.92	99%	41.8°
2036-09-07 Sun	29	—	unknown	22:15–05:20 (marginal, 7.08 h)	79.2° 03:45	7.97	96%	32.9°
2036-09-08 Mon	33	—	unknown	22:00–05:20 (marginal, 7.33 h)	79.1° 03:40	8.03	91%	26.4°
2036-09-09 Tue	43	—	unknown	21:40–05:25 (marginal, 7.75 h)	79.1° 03:40	8.08	84%	24.5°
2036-09-10 Wed	71	—	unknown	22:05–22:25 (good, 0.33 h)	79.2° 03:35	8.14	76%	28.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-08-12&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.