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: 08-13 (100), 08-14 (100), 08-15 (100), 08-16 (100), 08-17 (100) — by astronomy; check the weather when the night is within four days.

2045-08-13astronomy score per night — click a bar for that night2045-09-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-08-13 Sun	100	—	unknown	00:00–04:45 (good, 4.75 h)	79.2° 05:25	6.55	2%	123.6°
2045-08-14 Mon	100	—	unknown	23:55–04:45 (good, 4.83 h)	79.2° 05:20	6.61	7%	137.8°
2045-08-15 Tue	100	—	unknown	23:50–04:50 (good, 5.0 h)	79.2° 05:20	6.67	14%	151.0°
2045-08-16 Wed	100	—	unknown	23:45–04:50 (good, 5.08 h)	79.2° 05:15	6.72	24%	161.8°
2045-08-17 Thu	100	—	unknown	23:45–04:50 (good, 5.08 h)	79.2° 05:10	6.78	34%	165.4°
2045-08-18 Fri	100	—	unknown	23:40–04:55 (good, 5.25 h)	79.2° 05:05	6.84	44%	158.8°
2045-08-19 Sat	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 05:00	6.9	55%	148.2°
2045-08-20 Sun	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 05:00	6.95	64%	136.7°
2045-08-21 Mon	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 04:55	7.01	74%	125.1°
2045-08-22 Tue	100	—	unknown	23:35–05:00 (good, 5.42 h)	79.2° 04:50	7.07	82%	113.5°
2045-08-23 Wed	100	—	unknown	23:35–05:00 (good, 5.42 h)	79.2° 04:45	7.13	88%	102.0°
2045-08-24 Thu	100	—	unknown	23:45–05:00 (good, 5.25 h)	79.2° 04:45	7.18	94%	90.5°
2045-08-25 Fri	77	—	unknown	00:55–05:05 (good, 4.17 h)	79.2° 04:40	7.24	98%	79.0°
2045-08-26 Sat	64	—	unknown	02:45–05:05 (good, 2.33 h)	79.2° 04:35	7.3	100%	67.6°
2045-08-27 Sun	47	—	unknown	22:55–05:05 (marginal, 6.17 h)	79.2° 04:30	7.35	100%	56.2°
2045-08-28 Mon	33	—	unknown	23:00–05:05 (marginal, 6.08 h)	79.2° 04:25	7.41	98%	44.9°
2045-08-29 Tue	24	—	unknown	23:00–05:10 (marginal, 6.17 h)	79.2° 04:25	7.47	95%	33.8°
2045-08-30 Wed	24	—	unknown	22:50–05:10 (marginal, 6.33 h)	79.2° 04:20	7.52	90%	23.5°
2045-08-31 Thu	31	—	unknown	22:35–05:10 (marginal, 6.58 h)	79.2° 04:15	7.58	83%	15.8°
2045-09-01 Fri	42	—	unknown	22:20–05:15 (marginal, 6.92 h)	79.2° 04:10	7.63	75%	15.6°
2045-09-02 Sat	58	—	unknown	22:10–05:15 (marginal, 7.08 h)	79.2° 04:05	7.69	66%	23.6°
2045-09-03 Sun	75	—	unknown	22:35–05:00 (good, 6.42 h)	79.2° 04:05	7.74	55%	34.7°
2045-09-04 Mon	86	—	unknown	22:30–05:15 (good, 6.75 h)	79.2° 04:00	7.8	44%	47.1°
2045-09-05 Tue	94	—	unknown	22:30–05:20 (good, 6.83 h)	79.2° 03:55	7.86	34%	60.2°
2045-09-06 Wed	100	—	unknown	22:25–05:20 (good, 6.92 h)	79.2° 03:50	7.91	23%	73.9°
2045-09-07 Thu	100	—	unknown	22:20–05:20 (good, 7.0 h)	79.2° 03:45	7.96	14%	88.0°
2045-09-08 Fri	100	—	unknown	22:15–05:20 (good, 7.08 h)	79.2° 03:45	8.02	7%	102.5°
2045-09-09 Sat	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.2° 03:40	8.07	2%	117.0°
2045-09-10 Sun	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.2° 03:35	8.13	0%	131.4°
2045-09-11 Mon	100	—	unknown	22:05–05:25 (good, 7.33 h)	79.2° 03:30	8.18	1%	145.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-08-13&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.