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: 08-26 (100), 08-27 (100), 08-28 (100), 08-29 (100), 08-30 (100) — by astronomy; check the weather when the night is within four days.

2028-08-26astronomy score per night — click a bar for that night2028-09-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-08-26 Sat	100	—	unknown	23:10–05:05 (good, 5.92 h)	79.1° 04:35	7.3	49%	147.5°
2028-08-27 Sun	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.1° 04:30	7.36	59%	135.4°
2028-08-28 Mon	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.1° 04:25	7.42	69%	123.3°
2028-08-29 Tue	100	—	unknown	23:05–05:10 (good, 6.08 h)	79.1° 04:20	7.47	78%	111.2°
2028-08-30 Wed	100	—	unknown	23:10–05:10 (good, 6.0 h)	79.1° 04:20	7.53	86%	99.3°
2028-08-31 Thu	100	—	unknown	23:30–05:10 (good, 5.67 h)	79.1° 04:15	7.58	92%	87.5°
2028-09-01 Fri	100	—	unknown	00:50–05:15 (good, 4.42 h)	79.1° 04:10	7.64	96%	75.8°
2028-09-02 Sat	68	—	unknown	03:20–05:15 (good, 1.92 h)	79.1° 04:05	7.7	99%	64.3°
2028-09-03 Sun	49	—	unknown	22:30–05:15 (marginal, 6.75 h)	79.1° 04:00	7.75	100%	53.0°
2028-09-04 Mon	34	—	unknown	22:35–05:15 (marginal, 6.67 h)	79.1° 04:00	7.81	99%	41.8°
2028-09-05 Tue	23	—	unknown	22:35–05:20 (marginal, 6.75 h)	79.1° 03:55	7.86	96%	31.1°
2028-09-06 Wed	25	—	unknown	22:20–05:20 (marginal, 7.0 h)	79.1° 03:50	7.92	92%	21.4°
2028-09-07 Thu	32	—	unknown	22:05–05:20 (marginal, 7.25 h)	79.1° 03:45	7.97	86%	15.0°
2028-09-08 Fri	42	—	unknown	21:55–05:20 (marginal, 7.42 h)	79.1° 03:40	8.03	79%	16.4°
2028-09-09 Sat	55	—	unknown	21:40–05:25 (marginal, 7.75 h)	79.1° 03:40	8.08	71%	24.6°
2028-09-10 Sun	80	—	unknown	22:05–03:00 (good, 4.92 h)	79.1° 03:35	8.13	61%	35.4°
2028-09-11 Mon	86	—	unknown	22:05–05:25 (good, 7.33 h)	79.1° 03:30	8.19	51%	47.2°
2028-09-12 Tue	94	—	unknown	22:00–05:25 (good, 7.42 h)	79.1° 03:25	8.24	41%	59.7°
2028-09-13 Wed	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.1° 03:20	8.29	30%	72.7°
2028-09-14 Thu	100	—	unknown	21:50–05:30 (good, 7.67 h)	79.1° 03:20	8.35	20%	86.3°
2028-09-15 Fri	100	—	unknown	21:45–05:30 (good, 7.75 h)	79.1° 03:15	8.4	12%	100.3°
2028-09-16 Sat	100	—	unknown	21:45–05:30 (good, 7.75 h)	79.1° 03:10	8.45	5%	114.7°
2028-09-17 Sun	100	—	unknown	21:40–05:35 (good, 7.92 h)	79.1° 03:05	8.5	1%	129.2°
2028-09-18 Mon	100	—	unknown	21:35–05:35 (good, 8.0 h)	79.1° 03:05	8.56	0%	143.4°
2028-09-19 Tue	100	—	unknown	21:30–05:35 (good, 8.08 h)	79.1° 03:00	8.61	2%	156.4°
2028-09-20 Wed	100	—	unknown	21:30–05:35 (good, 8.08 h)	79.1° 02:55	8.66	7%	165.1°
2028-09-21 Thu	100	—	unknown	21:25–05:40 (good, 8.25 h)	79.1° 02:50	8.71	14%	162.0°
2028-09-22 Fri	100	—	unknown	21:20–05:40 (good, 8.33 h)	79.1° 02:45	8.76	23%	151.4°
2028-09-23 Sat	100	—	unknown	21:20–05:40 (good, 8.33 h)	79.1° 02:45	8.81	33%	139.1°
2028-09-24 Sun	100	—	unknown	21:15–05:40 (good, 8.42 h)	79.1° 02:40	8.86	44%	126.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-08-26&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.