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: 08-07 (100), 08-08 (100), 08-09 (100), 08-10 (100), 08-11 (100) — by astronomy; check the weather when the night is within four days.

2029-07-18astronomy score per night — click a bar for that night2029-08-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-07-18 Wed	65	—	unknown	01:40–04:05 (good, 2.42 h)	79.1° 07:10	5.14	54%	165.2°
2029-07-19 Thu	66	—	unknown	01:35–04:05 (good, 2.5 h)	79.1° 07:05	5.19	65%	160.6°
2029-07-20 Fri	68	—	unknown	01:40–04:05 (good, 2.42 h)	79.1° 07:00	5.24	76%	149.6°
2029-07-21 Sat	70	—	unknown	01:35–04:10 (good, 2.58 h)	79.1° 06:55	5.29	85%	137.0°
2029-07-22 Sun	70	—	unknown	01:35–04:10 (good, 2.58 h)	79.1° 06:50	5.34	92%	123.9°
2029-07-23 Mon	60	—	unknown	01:35–04:10 (good, 2.58 h)	79.1° 06:50	5.39	97%	110.7°
2029-07-24 Tue	50	—	unknown	01:40–04:15 (good, 2.58 h)	79.1° 06:45	5.44	100%	97.6°
2029-07-25 Wed	41	—	unknown	02:40–04:15 (good, 1.58 h)	79.1° 06:40	5.49	100%	84.8°
2029-07-26 Thu	33	—	unknown	03:55–04:15 (good, 0.33 h)	79.1° 06:35	5.54	98%	72.2°
2029-07-27 Fri	27	—	unknown	00:55–04:20 (marginal, 3.42 h)	79.1° 06:30	5.59	94%	60.0°
2029-07-28 Sat	22	—	unknown	00:50–04:20 (marginal, 3.5 h)	79.1° 06:30	5.65	88%	48.2°
2029-07-29 Sun	21	—	unknown	00:50–04:20 (marginal, 3.5 h)	79.1° 06:25	5.7	81%	36.9°
2029-07-30 Mon	23	—	unknown	00:40–04:25 (marginal, 3.75 h)	79.1° 06:20	5.75	73%	26.5°
2029-07-31 Tue	31	—	unknown	00:25–04:25 (marginal, 4.0 h)	79.1° 06:15	5.81	64%	18.0°
2029-08-01 Wed	41	—	unknown	02:40–04:25 (good, 1.75 h)	79.1° 06:15	5.86	55%	14.9°
2029-08-02 Thu	52	—	unknown	01:05–04:30 (good, 3.42 h)	79.1° 06:10	5.92	46%	19.9°
2029-08-03 Fri	66	—	unknown	00:35–04:30 (good, 3.92 h)	79.1° 06:05	5.97	36%	29.2°
2029-08-04 Sat	82	—	unknown	00:35–04:30 (good, 3.92 h)	79.1° 06:00	6.03	27%	40.0°
2029-08-05 Sun	93	—	unknown	00:30–04:30 (good, 4.0 h)	79.1° 05:55	6.09	19%	51.6°
2029-08-06 Mon	98	—	unknown	00:25–04:35 (good, 4.17 h)	79.1° 05:55	6.14	11%	63.8°
2029-08-07 Tue	100	—	unknown	00:20–04:35 (good, 4.25 h)	79.1° 05:50	6.2	6%	76.4°
2029-08-08 Wed	100	—	unknown	00:20–04:35 (good, 4.25 h)	79.1° 05:45	6.26	2%	89.5°
2029-08-09 Thu	100	—	unknown	00:15–04:40 (good, 4.42 h)	79.1° 05:40	6.31	0%	102.9°
2029-08-10 Fri	100	—	unknown	00:10–04:40 (good, 4.5 h)	79.1° 05:35	6.37	1%	116.5°
2029-08-11 Sat	100	—	unknown	00:05–04:40 (good, 4.58 h)	79.1° 05:35	6.43	5%	130.1°
2029-08-12 Sun	100	—	unknown	00:00–04:45 (good, 4.75 h)	79.1° 05:30	6.49	11%	143.5°
2029-08-13 Mon	100	—	unknown	00:00–04:45 (good, 4.75 h)	79.1° 05:25	6.54	19%	155.9°
2029-08-14 Tue	100	—	unknown	23:55–04:45 (good, 4.83 h)	79.1° 05:20	6.6	29%	164.4°
2029-08-15 Wed	100	—	unknown	23:50–04:50 (good, 5.0 h)	79.1° 05:20	6.66	40%	162.4°
2029-08-16 Thu	100	—	unknown	23:45–04:50 (good, 5.08 h)	79.1° 05:15	6.72	52%	152.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-07-18&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.