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: 10-11 (100), 10-12 (100), 10-13 (100), 10-14 (100), 10-15 (100) — by astronomy; check the weather when the night is within four days.

2028-10-11astronomy score per night — click a bar for that night2028-11-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-10-11 Wed	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:30	9.67	45%	81.9°
2028-10-12 Thu	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:30	9.71	34%	95.3°
2028-10-13 Fri	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:25	9.76	24%	109.0°
2028-10-14 Sat	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:20	9.8	15%	123.0°
2028-10-15 Sun	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:15	9.84	7%	137.1°
2028-10-16 Mon	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:15	9.89	2%	150.7°
2028-10-17 Tue	100	—	unknown	20:10–06:05 (good, 9.92 h)	79.1° 01:10	9.93	0%	162.0°
2028-10-18 Wed	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.1° 01:05	9.97	1%	164.9°
2028-10-19 Thu	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.1° 01:00	10.01	5%	156.3°
2028-10-20 Fri	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.1° 00:55	10.06	11%	144.0°
2028-10-21 Sat	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.1° 00:55	10.1	19%	131.2°
2028-10-22 Sun	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.1° 00:50	10.14	28%	118.4°
2028-10-23 Mon	100	—	unknown	20:05–06:15 (good, 10.17 h)	79.1° 00:45	10.18	37%	106.0°
2028-10-24 Tue	100	—	unknown	20:00–06:15 (good, 10.25 h)	79.1° 00:40	10.22	47%	93.8°
2028-10-25 Wed	100	—	unknown	20:00–06:10 (good, 10.17 h)	79.1° 00:35	10.26	57%	82.0°
2028-10-26 Thu	100	—	unknown	20:00–06:05 (good, 10.08 h)	79.1° 00:35	10.3	66%	70.4°
2028-10-27 Fri	99	—	unknown	21:30–06:00 (good, 8.5 h)	79.1° 00:30	10.33	75%	58.9°
2028-10-28 Sat	91	—	unknown	01:25–05:00 (good, 4.58 h)	79.1° 00:25	10.37	82%	47.7°
2028-10-29 Sun	83	—	unknown	03:55–04:55 (good, 1.0 h)	79.1° 23:20	10.41	89%	36.8°
2028-10-30 Mon	55	—	unknown	18:55–05:20 (marginal, 10.42 h)	79.1° 23:20	10.45	94%	26.4°
2028-10-31 Tue	33	—	unknown	00:50–04:50 (marginal, 4.0 h)	79.1° 23:15	10.48	98%	17.7°
2028-11-01 Wed	28	—	unknown	18:50–21:05 (marginal, 2.25 h)	79.1° 23:10	10.52	100%	14.7°
2028-11-02 Thu	30	—	unknown	18:50–21:40 (marginal, 2.83 h)	79.1° 23:05	10.56	100%	20.2°
2028-11-03 Fri	36	—	unknown	18:50–22:35 (marginal, 3.75 h)	79.1° 23:00	10.59	98%	30.1°
2028-11-04 Sat	55	—	unknown	18:50–03:20 (marginal, 8.5 h)	79.1° 23:00	10.63	94%	41.5°
2028-11-05 Sun	89	—	unknown	18:50–21:55 (good, 3.08 h)	79.1° 22:55	10.66	88%	53.5°
2028-11-06 Mon	97	—	unknown	18:45–01:25 (good, 6.67 h)	79.1° 22:50	10.69	80%	66.0°
2028-11-07 Tue	100	—	unknown	18:45–03:05 (good, 8.33 h)	79.1° 22:45	10.73	71%	78.8°
2028-11-08 Wed	100	—	unknown	18:45–03:55 (good, 9.17 h)	79.1° 22:40	10.76	61%	91.9°
2028-11-09 Thu	100	—	unknown	18:45–04:00 (good, 9.25 h)	79.1° 22:40	10.79	50%	105.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-10-11&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.