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: 09-30 (100), 10-01 (100), 10-02 (100), 10-03 (100), 10-04 (100) — by astronomy; check the weather when the night is within four days.

2029-09-26astronomy score per night — click a bar for that night2029-10-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-09-26 Wed	47	—	unknown	20:45–05:45 (marginal, 9.0 h)	79.1° 02:30	8.95	84%	23.4°
2029-09-27 Thu	75	—	unknown	21:00–21:25 (good, 0.42 h)	79.1° 02:30	9.0	77%	33.1°
2029-09-28 Fri	85	—	unknown	20:55–02:10 (good, 5.25 h)	79.1° 02:25	9.05	69%	44.0°
2029-09-29 Sat	92	—	unknown	20:55–05:40 (good, 8.75 h)	79.1° 02:20	9.1	59%	55.4°
2029-09-30 Sun	100	—	unknown	20:50–05:50 (good, 9.0 h)	79.1° 02:15	9.14	50%	67.2°
2029-10-01 Mon	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.1° 02:15	9.19	39%	79.4°
2029-10-02 Tue	100	—	unknown	20:40–05:50 (good, 9.17 h)	79.1° 02:10	9.24	29%	92.0°
2029-10-03 Wed	100	—	unknown	20:40–05:50 (good, 9.17 h)	79.1° 02:05	9.29	20%	105.1°
2029-10-04 Thu	100	—	unknown	20:35–05:50 (good, 9.25 h)	79.1° 02:00	9.34	12%	118.6°
2029-10-05 Fri	100	—	unknown	20:30–05:55 (good, 9.42 h)	79.1° 01:55	9.38	5%	132.3°
2029-10-06 Sat	100	—	unknown	20:30–05:55 (good, 9.42 h)	79.1° 01:55	9.43	1%	145.9°
2029-10-07 Sun	100	—	unknown	20:25–05:55 (good, 9.5 h)	79.1° 01:50	9.48	0%	158.2°
2029-10-08 Mon	100	—	unknown	20:25–05:55 (good, 9.5 h)	79.1° 01:45	9.52	2%	164.8°
2029-10-09 Tue	100	—	unknown	20:25–06:00 (good, 9.58 h)	79.1° 01:40	9.57	7%	159.1°
2029-10-10 Wed	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:35	9.61	14%	147.2°
2029-10-11 Thu	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:35	9.66	23%	133.9°
2029-10-12 Fri	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:30	9.7	33%	120.6°
2029-10-13 Sat	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.1° 01:25	9.75	44%	107.4°
2029-10-14 Sun	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:20	9.79	55%	94.6°
2029-10-15 Mon	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:20	9.83	65%	82.2°
2029-10-16 Tue	100	—	unknown	21:10–06:05 (good, 8.92 h)	79.1° 01:15	9.88	74%	70.0°
2029-10-17 Wed	99	—	unknown	23:20–06:05 (good, 6.75 h)	79.1° 01:10	9.92	82%	58.2°
2029-10-18 Thu	91	—	unknown	02:55–06:10 (good, 3.25 h)	79.1° 01:05	9.96	89%	46.7°
2029-10-19 Fri	83	—	unknown	05:40–06:10 (good, 0.5 h)	79.1° 01:00	10.0	94%	35.6°
2029-10-20 Sat	41	—	unknown	01:25–06:10 (marginal, 4.75 h)	79.1° 01:00	10.05	98%	25.5°
2029-10-21 Sun	31	—	unknown	03:00–06:10 (marginal, 3.17 h)	79.1° 00:55	10.09	100%	17.5°
2029-10-22 Mon	30	—	unknown	20:05–22:55 (marginal, 2.83 h)	79.1° 00:50	10.13	100%	15.5°
2029-10-23 Tue	35	—	unknown	20:05–23:40 (marginal, 3.58 h)	79.1° 00:45	10.17	98%	21.2°
2029-10-24 Wed	44	—	unknown	20:00–01:05 (marginal, 5.08 h)	79.1° 00:40	10.21	94%	30.5°
2029-10-25 Thu	83	—	unknown	20:00–20:10 (good, 0.17 h)	79.1° 00:40	10.25	89%	41.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-09-26&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.