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

2040-08-02astronomy score per night — click a bar for that night2040-08-31

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2040-08-02 Thu	87	—	unknown	00:40–04:30 (good, 3.83 h)	79.2° 06:10	5.94	22%	45.4°
2040-08-03 Fri	95	—	unknown	00:35–04:30 (good, 3.92 h)	79.2° 06:05	5.99	14%	55.9°
2040-08-04 Sat	99	—	unknown	00:35–04:30 (good, 3.92 h)	79.2° 06:00	6.05	8%	66.6°
2040-08-05 Sun	100	—	unknown	00:30–04:35 (good, 4.08 h)	79.2° 05:55	6.1	4%	77.5°
2040-08-06 Mon	100	—	unknown	00:25–04:35 (good, 4.17 h)	79.2° 05:50	6.16	1%	88.5°
2040-08-07 Tue	100	—	unknown	00:20–04:35 (good, 4.25 h)	79.2° 05:50	6.22	0%	99.5°
2040-08-08 Wed	100	—	unknown	00:15–04:40 (good, 4.42 h)	79.2° 05:45	6.28	1%	110.6°
2040-08-09 Thu	100	—	unknown	00:15–04:40 (good, 4.42 h)	79.2° 05:40	6.33	4%	121.6°
2040-08-10 Fri	100	—	unknown	00:10–04:40 (good, 4.5 h)	79.2° 05:35	6.39	8%	132.4°
2040-08-11 Sat	100	—	unknown	00:05–04:40 (good, 4.58 h)	79.2° 05:35	6.45	14%	142.7°
2040-08-12 Sun	100	—	unknown	00:00–04:45 (good, 4.75 h)	79.2° 05:30	6.5	22%	151.8°
2040-08-13 Mon	100	—	unknown	23:55–04:45 (good, 4.83 h)	79.2° 05:25	6.56	31%	157.7°
2040-08-14 Tue	100	—	unknown	23:55–04:45 (good, 4.83 h)	79.2° 05:20	6.62	41%	157.3°
2040-08-15 Wed	100	—	unknown	23:55–04:50 (good, 4.92 h)	79.2° 05:15	6.68	52%	150.4°
2040-08-16 Thu	100	—	unknown	23:50–04:50 (good, 5.0 h)	79.2° 05:15	6.73	63%	140.0°
2040-08-17 Fri	100	—	unknown	23:50–04:50 (good, 5.0 h)	79.2° 05:10	6.79	73%	127.8°
2040-08-18 Sat	100	—	unknown	23:50–04:55 (good, 5.08 h)	79.2° 05:05	6.85	83%	114.7°
2040-08-19 Sun	100	—	unknown	23:55–04:55 (good, 5.0 h)	79.2° 05:00	6.91	91%	101.0°
2040-08-20 Mon	100	—	unknown	00:15–04:55 (good, 4.67 h)	79.2° 04:55	6.96	97%	87.1°
2040-08-21 Tue	67	—	unknown	01:50–04:55 (good, 3.08 h)	79.2° 04:55	7.02	100%	73.1°
2040-08-22 Wed	48	—	unknown	23:10–05:00 (marginal, 5.83 h)	79.2° 04:50	7.08	99%	59.4°
2040-08-23 Thu	35	—	unknown	23:10–05:00 (marginal, 5.83 h)	79.2° 04:45	7.14	96%	46.4°
2040-08-24 Fri	28	—	unknown	23:05–05:00 (marginal, 5.92 h)	79.2° 04:40	7.19	91%	34.6°
2040-08-25 Sat	32	—	unknown	22:55–05:05 (marginal, 6.17 h)	79.2° 04:35	7.25	84%	25.4°
2040-08-26 Sun	42	—	unknown	22:40–05:05 (marginal, 6.42 h)	79.2° 04:35	7.31	75%	21.5°
2040-08-27 Mon	56	—	unknown	22:35–05:05 (marginal, 6.5 h)	79.2° 04:30	7.36	65%	24.7°
2040-08-28 Tue	80	—	unknown	23:00–05:00 (good, 6.0 h)	79.2° 04:25	7.42	55%	32.6°
2040-08-29 Wed	85	—	unknown	22:55–05:10 (good, 6.25 h)	79.2° 04:20	7.48	46%	42.4°
2040-08-30 Thu	90	—	unknown	22:50–05:10 (good, 6.33 h)	79.2° 04:20	7.53	36%	52.8°
2040-08-31 Fri	96	—	unknown	22:45–05:10 (good, 6.42 h)	79.2° 04:15	7.59	27%	63.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2040-08-02&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.