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: 01-12 (100), 01-13 (100), 01-14 (100), 01-15 (100), 01-16 (100) — by astronomy; check the weather when the night is within four days.

2039-01-09astronomy score per night — click a bar for that night2039-02-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-01-09 Sun	49	—	unknown	18:50–19:45 (good, 0.92 h)	79.2° 18:40	11.34	100%	70.7°
2039-01-10 Mon	65	—	unknown	18:50–21:40 (good, 2.83 h)	79.2° 18:35	11.33	100%	82.2°
2039-01-11 Tue	81	—	unknown	18:50–22:55 (good, 4.08 h)	79.2° 18:35	11.31	98%	93.9°
2039-01-12 Wed	100	—	unknown	18:55–23:40 (good, 4.75 h)	79.2° 18:30	11.29	94%	105.8°
2039-01-13 Thu	100	—	unknown	18:55–23:45 (good, 4.83 h)	79.2° 18:25	11.27	88%	117.7°
2039-01-14 Fri	100	—	unknown	18:55–23:45 (good, 4.83 h)	79.2° 18:20	11.25	80%	129.4°
2039-01-15 Sat	100	—	unknown	18:55–23:45 (good, 4.83 h)	79.2° 18:15	11.23	70%	140.5°
2039-01-16 Sun	100	—	unknown	18:55–23:45 (good, 4.83 h)	79.2° 18:15	11.21	59%	150.1°
2039-01-17 Mon	100	—	unknown	19:00–23:40 (good, 4.67 h)	79.2° 18:10	11.18	48%	155.8°
2039-01-18 Tue	100	—	unknown	19:00–23:40 (good, 4.67 h)	79.2° 18:05	11.16	37%	154.5°
2039-01-19 Wed	100	—	unknown	19:00–23:35 (good, 4.58 h)	79.2° 18:00	11.14	26%	146.9°
2039-01-20 Thu	100	—	unknown	19:00–23:30 (good, 4.5 h)	79.2° 18:00	11.11	17%	136.1°
2039-01-21 Fri	100	—	unknown	19:00–23:25 (good, 4.42 h)	79.2° 17:55	11.09	9%	123.8°
2039-01-22 Sat	100	—	unknown	19:05–23:20 (good, 4.25 h)	79.2° 17:50	11.06	4%	111.0°
2039-01-23 Sun	100	—	unknown	19:05–23:20 (good, 4.25 h)	79.2° 17:45	11.03	1%	98.0°
2039-01-24 Mon	100	—	unknown	19:05–23:15 (good, 4.17 h)	79.2° 17:40	11.01	0%	85.1°
2039-01-25 Tue	100	—	unknown	19:05–23:10 (good, 4.08 h)	79.2° 17:40	10.98	2%	72.6°
2039-01-26 Wed	100	—	unknown	19:05–23:05 (good, 4.0 h)	79.2° 17:35	10.95	7%	60.5°
2039-01-27 Thu	95	—	unknown	19:10–23:00 (good, 3.83 h)	79.2° 17:30	10.92	13%	49.2°
2039-01-28 Fri	84	—	unknown	19:10–23:00 (good, 3.83 h)	79.2° 17:25	10.89	20%	38.9°
2039-01-29 Sat	69	—	unknown	19:10–22:55 (good, 3.75 h)	79.2° 17:20	10.86	29%	30.3°
2039-01-30 Sun	55	—	unknown	19:10–22:30 (good, 3.33 h)	79.2° 17:20	10.83	38%	24.7°
2039-01-31 Mon	42	—	unknown	19:15–21:35 (good, 2.33 h)	79.2° 17:15	10.79	48%	24.1°
2039-02-01 Tue	31	—	unknown	19:15–23:05 (marginal, 3.83 h)	79.2° 17:10	10.76	57%	28.6°
2039-02-02 Wed	25	—	unknown	19:15–22:50 (marginal, 3.58 h)	79.2° 17:05	10.73	66%	36.3°
2039-02-03 Thu	23	—	unknown	19:15–22:40 (marginal, 3.42 h)	79.2° 17:00	10.7	75%	45.6°
2039-02-04 Fri	23	—	unknown	19:15–22:35 (marginal, 3.33 h)	79.2° 17:00	10.66	83%	55.9°
2039-02-05 Sat	25	—	unknown	19:20–22:30 (marginal, 3.17 h)	79.2° 16:55	10.63	89%	66.9°
2039-02-06 Sun	30	—	unknown	19:20–19:40 (good, 0.33 h)	79.2° 16:50	10.59	95%	78.3°
2039-02-07 Mon	38	—	unknown	19:20–20:40 (good, 1.33 h)	79.2° 16:45	10.56	98%	90.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-01-09&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.