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: 01-21 (100), 01-22 (100), 01-23 (100), 01-24 (100), 01-25 (100) — by astronomy; check the weather when the night is within four days.

2030-01-19astronomy score per night — click a bar for that night2030-02-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-01-19 Sat	65	—	unknown	19:00–22:00 (good, 3.0 h)	79.1° 18:00	11.13	100%	91.0°
2030-01-20 Sun	80	—	unknown	19:00–23:05 (good, 4.08 h)	79.1° 17:55	11.11	98%	103.7°
2030-01-21 Mon	100	—	unknown	19:00–23:10 (good, 4.17 h)	79.1° 17:50	11.08	94%	116.6°
2030-01-22 Tue	100	—	unknown	19:05–23:10 (good, 4.08 h)	79.1° 17:50	11.05	88%	129.5°
2030-01-23 Wed	100	—	unknown	19:05–23:10 (good, 4.08 h)	79.1° 17:45	11.03	80%	142.2°
2030-01-24 Thu	100	—	unknown	19:05–23:15 (good, 4.17 h)	79.1° 17:40	11.0	70%	154.2°
2030-01-25 Fri	100	—	unknown	19:05–23:10 (good, 4.08 h)	79.1° 17:35	10.97	59%	163.2°
2030-01-26 Sat	100	—	unknown	19:10–23:05 (good, 3.92 h)	79.1° 17:35	10.94	48%	163.2°
2030-01-27 Sun	100	—	unknown	19:10–23:00 (good, 3.83 h)	79.1° 17:30	10.91	37%	154.1°
2030-01-28 Mon	99	—	unknown	19:10–22:55 (good, 3.75 h)	79.1° 17:25	10.88	26%	141.9°
2030-01-29 Tue	97	—	unknown	19:10–22:55 (good, 3.75 h)	79.1° 17:20	10.85	17%	128.7°
2030-01-30 Wed	96	—	unknown	19:10–22:50 (good, 3.67 h)	79.1° 17:15	10.82	9%	115.3°
2030-01-31 Thu	93	—	unknown	19:15–22:45 (good, 3.5 h)	79.1° 17:15	10.79	4%	101.8°
2030-02-01 Fri	91	—	unknown	19:15–22:40 (good, 3.42 h)	79.1° 17:10	10.76	1%	88.4°
2030-02-02 Sat	88	—	unknown	19:15–22:35 (good, 3.33 h)	79.1° 17:05	10.72	0%	75.2°
2030-02-03 Sun	86	—	unknown	19:15–22:35 (good, 3.33 h)	79.1° 17:00	10.69	2%	62.4°
2030-02-04 Mon	82	—	unknown	19:20–22:30 (good, 3.17 h)	79.1° 16:55	10.65	6%	50.1°
2030-02-05 Tue	75	—	unknown	19:20–22:25 (good, 3.08 h)	79.1° 16:55	10.62	12%	38.3°
2030-02-06 Wed	65	—	unknown	19:20–22:20 (good, 3.0 h)	79.1° 16:50	10.58	19%	27.5°
2030-02-07 Thu	54	—	unknown	19:20–22:05 (good, 2.75 h)	79.1° 16:45	10.55	27%	18.8°
2030-02-08 Fri	44	—	unknown	19:20–21:55 (good, 2.58 h)	79.1° 16:40	10.51	36%	15.4°
2030-02-09 Sat	33	—	unknown	19:25–20:50 (good, 1.42 h)	79.1° 16:40	10.48	45%	20.0°
2030-02-10 Sun	25	—	unknown	19:25–22:25 (marginal, 3.0 h)	79.1° 16:35	10.44	54%	28.9°
2030-02-11 Mon	20	—	unknown	19:25–22:15 (marginal, 2.83 h)	79.1° 16:30	10.4	64%	39.3°
2030-02-12 Tue	19	—	unknown	19:25–22:05 (marginal, 2.67 h)	79.1° 16:25	10.36	72%	50.5°
2030-02-13 Wed	19	—	unknown	19:30–22:05 (marginal, 2.58 h)	79.1° 16:20	10.32	81%	62.1°
2030-02-14 Thu	22	—	unknown	19:30–22:05 (marginal, 2.58 h)	79.1° 16:20	10.28	88%	74.1°
2030-02-15 Fri	26	—	unknown	19:30–20:00 (good, 0.5 h)	79.1° 16:15	10.24	94%	86.4°
2030-02-16 Sat	32	—	unknown	19:30–21:00 (good, 1.5 h)	79.1° 16:10	10.2	98%	99.2°
2030-02-17 Sun	38	—	unknown	19:30–21:20 (good, 1.83 h)	79.1° 16:05	10.16	100%	112.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-01-19&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.