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

2037-08-29astronomy score per night — click a bar for that night2037-09-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-08-29 Sat	34	—	unknown	22:40–05:10 (marginal, 6.5 h)	79.1° 04:25	7.46	85%	26.9°
2037-08-30 Sun	43	—	unknown	22:25–05:10 (marginal, 6.75 h)	79.2° 04:20	7.52	78%	24.5°
2037-08-31 Mon	66	—	unknown	22:45–23:00 (good, 0.25 h)	79.2° 04:15	7.57	69%	27.4°
2037-09-01 Tue	82	—	unknown	22:45–03:55 (good, 5.17 h)	79.2° 04:10	7.63	60%	34.3°
2037-09-02 Wed	87	—	unknown	22:40–05:15 (good, 6.58 h)	79.2° 04:05	7.69	50%	43.7°
2037-09-03 Thu	93	—	unknown	22:35–05:15 (good, 6.67 h)	79.2° 04:05	7.74	40%	54.4°
2037-09-04 Fri	99	—	unknown	22:30–05:15 (good, 6.75 h)	79.2° 04:00	7.8	29%	66.1°
2037-09-05 Sat	100	—	unknown	22:30–05:20 (good, 6.83 h)	79.2° 03:55	7.85	20%	78.5°
2037-09-06 Sun	100	—	unknown	22:25–05:20 (good, 6.92 h)	79.2° 03:50	7.91	12%	91.5°
2037-09-07 Mon	100	—	unknown	22:20–05:20 (good, 7.0 h)	79.1° 03:45	7.96	5%	104.8°
2037-09-08 Tue	100	—	unknown	22:15–05:20 (good, 7.08 h)	79.2° 03:45	8.02	1%	118.3°
2037-09-09 Wed	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.2° 03:40	8.07	0%	131.4°
2037-09-10 Thu	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.2° 03:35	8.12	2%	143.3°
2037-09-11 Fri	100	—	unknown	22:05–05:25 (good, 7.33 h)	79.2° 03:30	8.18	7%	152.4°
2037-09-12 Sat	100	—	unknown	22:00–05:25 (good, 7.42 h)	79.1° 03:30	8.23	15%	155.5°
2037-09-13 Sun	100	—	unknown	22:00–05:30 (good, 7.5 h)	79.2° 03:25	8.28	24%	151.0°
2037-09-14 Mon	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.2° 03:20	8.34	34%	142.0°
2037-09-15 Tue	100	—	unknown	21:50–05:30 (good, 7.67 h)	79.2° 03:15	8.39	45%	131.3°
2037-09-16 Wed	100	—	unknown	21:50–05:30 (good, 7.67 h)	79.2° 03:10	8.44	55%	120.0°
2037-09-17 Thu	100	—	unknown	21:50–05:35 (good, 7.75 h)	79.2° 03:10	8.49	65%	108.7°
2037-09-18 Fri	100	—	unknown	21:55–05:35 (good, 7.67 h)	79.2° 03:05	8.55	74%	97.4°
2037-09-19 Sat	100	—	unknown	22:00–05:35 (good, 7.58 h)	79.2° 03:00	8.6	82%	86.3°
2037-09-20 Sun	100	—	unknown	23:05–05:35 (good, 6.5 h)	79.2° 02:55	8.65	89%	75.3°
2037-09-21 Mon	100	—	unknown	00:35–05:40 (good, 5.08 h)	79.2° 02:50	8.7	94%	64.6°
2037-09-22 Tue	66	—	unknown	04:00–05:40 (good, 1.67 h)	79.2° 02:50	8.75	98%	54.2°
2037-09-23 Wed	56	—	unknown	21:10–05:40 (marginal, 8.5 h)	79.2° 02:45	8.8	100%	44.3°
2037-09-24 Thu	39	—	unknown	21:10–05:40 (marginal, 8.5 h)	79.2° 02:40	8.85	100%	35.3°
2037-09-25 Fri	32	—	unknown	21:00–05:40 (marginal, 8.67 h)	79.2° 02:35	8.9	98%	28.1°
2037-09-26 Sat	37	—	unknown	20:50–05:45 (marginal, 8.92 h)	79.1° 02:35	8.95	94%	24.5°
2037-09-27 Sun	58	—	unknown	21:00–21:05 (good, 0.08 h)	79.2° 02:30	9.0	89%	26.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-08-29&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.