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: 01-05 (100), 01-06 (100), 01-07 (100), 01-08 (100), 01-09 (100) — by astronomy; check the weather when the night is within four days.

2045-01-04astronomy score per night — click a bar for that night2045-02-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-01-04 Wed	82	—	unknown	18:45–23:15 (good, 4.5 h)	79.2° 19:00	11.41	96%	92.2°
2045-01-05 Thu	100	—	unknown	18:45–00:05 (good, 5.33 h)	79.2° 18:55	11.4	91%	106.7°
2045-01-06 Fri	100	—	unknown	18:50–00:15 (good, 5.42 h)	79.2° 18:50	11.38	83%	120.9°
2045-01-07 Sat	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:45	11.37	73%	134.4°
2045-01-08 Sun	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:45	11.35	63%	147.0°
2045-01-09 Mon	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:40	11.33	52%	158.0°
2045-01-10 Tue	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:35	11.32	42%	164.8°
2045-01-11 Wed	100	—	unknown	18:55–00:05 (good, 5.17 h)	79.2° 18:30	11.3	32%	162.6°
2045-01-12 Thu	100	—	unknown	18:55–00:00 (good, 5.08 h)	79.2° 18:25	11.28	23%	154.0°
2045-01-13 Fri	100	—	unknown	18:55–23:55 (good, 5.0 h)	79.2° 18:25	11.26	16%	143.4°
2045-01-14 Sat	100	—	unknown	18:55–23:50 (good, 4.92 h)	79.2° 18:20	11.24	9%	132.3°
2045-01-15 Sun	100	—	unknown	18:55–23:50 (good, 4.92 h)	79.2° 18:15	11.22	5%	121.0°
2045-01-16 Mon	100	—	unknown	19:00–23:45 (good, 4.75 h)	79.2° 18:10	11.19	2%	109.7°
2045-01-17 Tue	100	—	unknown	19:00–23:40 (good, 4.67 h)	79.2° 18:05	11.17	0%	98.3°
2045-01-18 Wed	100	—	unknown	19:00–23:35 (good, 4.58 h)	79.2° 18:05	11.15	0%	86.8°
2045-01-19 Thu	100	—	unknown	19:00–23:30 (good, 4.5 h)	79.2° 18:00	11.12	3%	75.4°
2045-01-20 Fri	100	—	unknown	19:00–23:30 (good, 4.5 h)	79.2° 17:55	11.1	7%	63.9°
2045-01-21 Sat	97	—	unknown	19:05–23:25 (good, 4.33 h)	79.2° 17:50	11.07	12%	52.4°
2045-01-22 Sun	91	—	unknown	19:05–23:20 (good, 4.25 h)	79.2° 17:50	11.05	19%	41.1°
2045-01-23 Mon	80	—	unknown	19:05–23:15 (good, 4.17 h)	79.2° 17:45	11.02	27%	30.0°
2045-01-24 Tue	64	—	unknown	19:05–22:55 (good, 3.83 h)	79.2° 17:40	10.99	37%	20.1°
2045-01-25 Wed	48	—	unknown	19:05–22:15 (good, 3.17 h)	79.2° 17:35	10.96	47%	14.8°
2045-01-26 Thu	34	—	unknown	19:10–23:25 (marginal, 4.25 h)	79.2° 17:30	10.93	58%	19.2°
2045-01-27 Fri	23	—	unknown	19:10–23:05 (marginal, 3.92 h)	79.2° 17:30	10.9	68%	29.7°
2045-01-28 Sat	21	—	unknown	19:10–22:55 (marginal, 3.75 h)	79.2° 17:25	10.87	78%	42.5°
2045-01-29 Sun	23	—	unknown	19:10–22:50 (marginal, 3.67 h)	79.2° 17:20	10.84	87%	56.2°
2045-01-30 Mon	31	—	unknown	19:10–22:55 (marginal, 3.75 h)	79.2° 17:15	10.81	94%	70.5°
2045-01-31 Tue	41	—	unknown	19:15–20:35 (good, 1.33 h)	79.2° 17:10	10.78	99%	85.2°
2045-02-01 Wed	55	—	unknown	19:15–22:00 (good, 2.75 h)	79.2° 17:10	10.74	100%	100.0°
2045-02-02 Thu	68	—	unknown	19:15–22:20 (good, 3.08 h)	79.2° 17:05	10.71	98%	114.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-01-04&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.