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: 08-02 (100), 08-03 (100), 08-04 (100), 08-05 (100), 08-06 (100) — by astronomy; check the weather when the night is within four days.

2030-07-23astronomy score per night — click a bar for that night2030-08-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-07-23 Tue	49	—	unknown	01:35–04:10 (good, 2.58 h)	79.1° 06:50	5.37	35%	22.7°
2030-07-24 Wed	61	—	unknown	01:20–04:15 (good, 2.92 h)	79.1° 06:45	5.42	26%	32.2°
2030-07-25 Thu	71	—	unknown	01:15–04:15 (good, 3.0 h)	79.1° 06:40	5.48	18%	42.7°
2030-07-26 Fri	79	—	unknown	01:10–04:15 (good, 3.08 h)	79.1° 06:35	5.53	12%	53.8°
2030-07-27 Sat	87	—	unknown	01:05–04:20 (good, 3.25 h)	79.1° 06:35	5.58	6%	65.2°
2030-07-28 Sun	90	—	unknown	01:00–04:20 (good, 3.33 h)	79.1° 06:30	5.63	2%	76.9°
2030-07-29 Mon	92	—	unknown	01:00–04:20 (good, 3.33 h)	79.1° 06:25	5.69	0%	88.8°
2030-07-30 Tue	93	—	unknown	00:55–04:20 (good, 3.42 h)	79.1° 06:20	5.74	0%	100.9°
2030-07-31 Wed	96	—	unknown	00:50–04:25 (good, 3.58 h)	79.1° 06:15	5.79	2%	113.2°
2030-08-01 Thu	99	—	unknown	00:45–04:25 (good, 3.67 h)	79.1° 06:15	5.85	7%	125.6°
2030-08-02 Fri	100	—	unknown	00:40–04:25 (good, 3.75 h)	79.1° 06:10	5.9	13%	137.9°
2030-08-03 Sat	100	—	unknown	00:40–04:30 (good, 3.83 h)	79.1° 06:05	5.96	21%	149.8°
2030-08-04 Sun	100	—	unknown	00:35–04:30 (good, 3.92 h)	79.1° 06:00	6.02	31%	159.9°
2030-08-05 Mon	100	—	unknown	00:30–04:30 (good, 4.0 h)	79.1° 06:00	6.07	41%	164.0°
2030-08-06 Tue	100	—	unknown	00:25–04:35 (good, 4.17 h)	79.1° 05:55	6.13	53%	157.9°
2030-08-07 Wed	100	—	unknown	00:30–04:35 (good, 4.08 h)	79.1° 05:50	6.19	64%	146.6°
2030-08-08 Thu	100	—	unknown	00:25–04:35 (good, 4.17 h)	79.1° 05:45	6.24	75%	133.7°
2030-08-09 Fri	100	—	unknown	00:25–04:40 (good, 4.25 h)	79.1° 05:40	6.3	84%	120.2°
2030-08-10 Sat	100	—	unknown	00:30–04:40 (good, 4.17 h)	79.1° 05:40	6.36	92%	106.4°
2030-08-11 Sun	76	—	unknown	00:40–04:40 (good, 4.0 h)	79.1° 05:35	6.41	97%	92.6°
2030-08-12 Mon	59	—	unknown	02:05–04:45 (good, 2.67 h)	79.1° 05:30	6.47	100%	78.9°
2030-08-13 Tue	43	—	unknown	04:35–04:45 (good, 0.17 h)	79.1° 05:25	6.53	100%	65.5°
2030-08-14 Wed	31	—	unknown	23:50–04:45 (marginal, 4.92 h)	79.1° 05:20	6.59	97%	52.5°
2030-08-15 Thu	24	—	unknown	23:50–04:50 (marginal, 5.0 h)	79.1° 05:20	6.64	92%	40.2°
2030-08-16 Fri	21	—	unknown	23:45–04:50 (marginal, 5.08 h)	79.1° 05:15	6.7	86%	29.0°
2030-08-17 Sat	29	—	unknown	23:30–04:50 (marginal, 5.33 h)	79.1° 05:10	6.76	78%	19.8°
2030-08-18 Sun	39	—	unknown	23:15–04:50 (marginal, 5.58 h)	79.1° 05:05	6.82	70%	16.1°
2030-08-19 Mon	53	—	unknown	02:05–02:55 (good, 0.83 h)	79.1° 05:05	6.87	61%	20.3°
2030-08-20 Tue	69	—	unknown	23:55–04:55 (good, 5.0 h)	79.1° 05:00	6.93	51%	29.1°
2030-08-21 Wed	84	—	unknown	23:30–04:55 (good, 5.42 h)	79.1° 04:55	6.99	42%	39.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-07-23&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.