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: 08-12 (100), 08-13 (100), 08-14 (100), 08-15 (100), 08-16 (100) — by astronomy; check the weather when the night is within four days.

2042-07-27astronomy score per night — click a bar for that night2042-08-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-07-27 Sun	87	—	unknown	01:10–04:20 (good, 3.17 h)	79.2° 06:35	5.58	75%	144.8°
2042-07-28 Mon	88	—	unknown	01:10–04:20 (good, 3.17 h)	79.2° 06:30	5.64	84%	133.7°
2042-07-29 Tue	88	—	unknown	01:05–04:20 (good, 3.25 h)	79.2° 06:25	5.69	90%	121.8°
2042-07-30 Wed	84	—	unknown	01:10–04:25 (good, 3.25 h)	79.2° 06:20	5.74	96%	109.2°
2042-07-31 Thu	63	—	unknown	01:15–04:25 (good, 3.17 h)	79.2° 06:20	5.8	99%	96.2°
2042-08-01 Fri	50	—	unknown	02:05–04:25 (good, 2.33 h)	79.2° 06:15	5.85	100%	82.9°
2042-08-02 Sat	39	—	unknown	03:30–04:25 (good, 0.92 h)	79.2° 06:10	5.91	98%	69.3°
2042-08-03 Sun	31	—	unknown	00:25–04:30 (marginal, 4.08 h)	79.2° 06:05	5.97	93%	55.7°
2042-08-04 Mon	26	—	unknown	00:20–04:30 (marginal, 4.17 h)	79.2° 06:00	6.02	86%	42.5°
2042-08-05 Tue	25	—	unknown	00:15–04:30 (marginal, 4.25 h)	79.2° 06:00	6.08	77%	30.2°
2042-08-06 Wed	34	—	unknown	00:05–04:35 (marginal, 4.5 h)	79.2° 05:55	6.13	67%	20.7°
2042-08-07 Thu	47	—	unknown	01:40–04:35 (good, 2.92 h)	79.2° 05:50	6.19	56%	18.6°
2042-08-08 Fri	62	—	unknown	00:40–04:35 (good, 3.92 h)	79.2° 05:45	6.25	44%	25.4°
2042-08-09 Sat	81	—	unknown	00:15–04:40 (good, 4.42 h)	79.2° 05:40	6.3	34%	36.2°
2042-08-10 Sun	90	—	unknown	00:10–04:40 (good, 4.5 h)	79.2° 05:40	6.36	24%	48.3°
2042-08-11 Mon	95	—	unknown	00:05–04:40 (good, 4.58 h)	79.2° 05:35	6.42	15%	60.6°
2042-08-12 Tue	100	—	unknown	00:05–04:45 (good, 4.67 h)	79.2° 05:30	6.48	8%	73.0°
2042-08-13 Wed	100	—	unknown	00:00–04:45 (good, 4.75 h)	79.2° 05:25	6.53	4%	85.3°
2042-08-14 Thu	100	—	unknown	23:55–04:45 (good, 4.83 h)	79.2° 05:25	6.59	1%	97.4°
2042-08-15 Fri	100	—	unknown	23:50–04:50 (good, 5.0 h)	79.2° 05:20	6.65	0%	109.3°
2042-08-16 Sat	100	—	unknown	23:45–04:50 (good, 5.08 h)	79.2° 05:15	6.71	2%	120.9°
2042-08-17 Sun	100	—	unknown	23:45–04:50 (good, 5.08 h)	79.2° 05:10	6.76	5%	132.1°
2042-08-18 Mon	100	—	unknown	23:40–04:50 (good, 5.17 h)	79.2° 05:05	6.82	9%	142.7°
2042-08-19 Tue	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 05:05	6.88	16%	152.4°
2042-08-20 Wed	100	—	unknown	23:30–04:55 (good, 5.42 h)	79.2° 05:00	6.94	23%	159.7°
2042-08-21 Thu	100	—	unknown	23:30–04:55 (good, 5.42 h)	79.2° 04:55	6.99	32%	161.8°
2042-08-22 Fri	100	—	unknown	23:25–05:00 (good, 5.58 h)	79.2° 04:50	7.05	41%	157.2°
2042-08-23 Sat	100	—	unknown	23:25–05:00 (good, 5.58 h)	79.2° 04:45	7.11	50%	148.4°
2042-08-24 Sun	100	—	unknown	23:20–05:00 (good, 5.67 h)	79.2° 04:45	7.17	60%	138.0°
2042-08-25 Mon	100	—	unknown	23:20–05:00 (good, 5.67 h)	79.2° 04:40	7.22	70%	126.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-07-27&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.