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: 08-20 (100), 08-21 (100), 09-03 (100), 09-04 (100), 09-05 (100) — by astronomy; check the weather when the night is within four days.

2029-08-20astronomy score per night — click a bar for that night2029-09-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-08-20 Mon	100	—	unknown	23:50–04:55 (good, 5.08 h)	79.1° 05:00	6.95	90%	101.4°
2029-08-21 Tue	100	—	unknown	00:15–04:55 (good, 4.67 h)	79.1° 04:55	7.0	95%	88.7°
2029-08-22 Wed	72	—	unknown	01:40–05:00 (good, 3.33 h)	79.1° 04:50	7.06	98%	76.2°
2029-08-23 Thu	53	—	unknown	04:15–05:00 (good, 0.75 h)	79.1° 04:45	7.12	100%	64.0°
2029-08-24 Fri	38	—	unknown	23:10–05:00 (marginal, 5.83 h)	79.1° 04:40	7.17	99%	52.1°
2029-08-25 Sat	27	—	unknown	23:15–05:05 (marginal, 5.83 h)	79.1° 04:40	7.23	96%	40.6°
2029-08-26 Sun	20	—	unknown	23:10–05:05 (marginal, 5.92 h)	79.1° 04:35	7.29	92%	29.8°
2029-08-27 Mon	26	—	unknown	22:55–05:05 (marginal, 6.17 h)	79.1° 04:30	7.35	86%	20.5°
2029-08-28 Tue	35	—	unknown	22:40–05:05 (marginal, 6.42 h)	79.1° 04:25	7.4	79%	15.2°
2029-08-29 Wed	46	—	unknown	22:30–05:10 (marginal, 6.67 h)	79.1° 04:20	7.46	71%	17.7°
2029-08-30 Thu	61	—	unknown	00:25–02:25 (good, 2.0 h)	79.1° 04:20	7.51	62%	26.0°
2029-08-31 Fri	81	—	unknown	22:45–05:10 (good, 6.42 h)	79.1° 04:15	7.57	52%	36.3°
2029-09-01 Sat	87	—	unknown	22:45–05:10 (good, 6.42 h)	79.1° 04:10	7.63	43%	47.4°
2029-09-02 Sun	95	—	unknown	22:40–05:15 (good, 6.58 h)	79.1° 04:05	7.68	33%	59.2°
2029-09-03 Mon	100	—	unknown	22:35–05:15 (good, 6.67 h)	79.1° 04:05	7.74	24%	71.5°
2029-09-04 Tue	100	—	unknown	22:30–05:15 (good, 6.75 h)	79.1° 04:00	7.79	16%	84.2°
2029-09-05 Wed	100	—	unknown	22:30–05:20 (good, 6.83 h)	79.1° 03:55	7.85	8%	97.3°
2029-09-06 Thu	100	—	unknown	22:25–05:20 (good, 6.92 h)	79.1° 03:50	7.9	3%	110.9°
2029-09-07 Fri	100	—	unknown	22:20–05:20 (good, 7.0 h)	79.1° 03:45	7.96	0%	124.7°
2029-09-08 Sat	100	—	unknown	22:15–05:20 (good, 7.08 h)	79.1° 03:45	8.01	0%	138.4°
2029-09-09 Sun	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.1° 03:40	8.07	3%	151.6°
2029-09-10 Mon	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.1° 03:35	8.12	9%	162.3°
2029-09-11 Tue	100	—	unknown	22:05–05:25 (good, 7.33 h)	79.1° 03:30	8.17	17%	164.0°
2029-09-12 Wed	100	—	unknown	22:00–05:25 (good, 7.42 h)	79.1° 03:25	8.23	27%	155.2°
2029-09-13 Thu	100	—	unknown	22:00–05:30 (good, 7.5 h)	79.1° 03:25	8.28	37%	142.9°
2029-09-14 Fri	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.1° 03:20	8.33	48%	130.0°
2029-09-15 Sat	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.1° 03:15	8.39	60%	117.1°
2029-09-16 Sun	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.1° 03:10	8.44	70%	104.3°
2029-09-17 Mon	100	—	unknown	22:05–05:35 (good, 7.5 h)	79.1° 03:10	8.49	79%	91.7°
2029-09-18 Tue	100	—	unknown	22:50–05:35 (good, 6.75 h)	79.1° 03:05	8.54	86%	79.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-08-20&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.