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: 12-27 (100), 12-28 (100), 12-29 (100), 12-30 (100), 12-31 (100) — by astronomy; check the weather when the night is within four days.

2046-12-27astronomy score per night — click a bar for that night2047-01-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-12-27 Thu	100	—	unknown	18:40–01:05 (good, 6.42 h)	79.2° 19:30	11.49	0%	110.0°
2046-12-28 Fri	100	—	unknown	18:40–01:00 (good, 6.33 h)	79.2° 19:30	11.48	3%	96.9°
2046-12-29 Sat	100	—	unknown	18:40–00:55 (good, 6.25 h)	79.2° 19:25	11.48	7%	84.2°
2046-12-30 Sun	100	—	unknown	18:40–00:55 (good, 6.25 h)	79.2° 19:20	11.47	13%	71.8°
2046-12-31 Mon	100	—	unknown	18:45–00:50 (good, 6.08 h)	79.2° 19:15	11.46	20%	59.8°
2047-01-01 Tue	93	—	unknown	18:45–00:45 (good, 6.0 h)	79.2° 19:10	11.45	29%	48.2°
2047-01-02 Wed	86	—	unknown	18:45–00:40 (good, 5.92 h)	79.2° 19:10	11.44	38%	37.0°
2047-01-03 Thu	71	—	unknown	18:45–00:15 (good, 5.5 h)	79.2° 19:05	11.43	47%	26.6°
2047-01-04 Fri	59	—	unknown	20:35–22:35 (good, 2.0 h)	79.2° 19:00	11.42	57%	17.8°
2047-01-05 Sat	42	—	unknown	18:45–00:50 (marginal, 6.08 h)	79.2° 18:55	11.4	66%	14.2°
2047-01-06 Sun	29	—	unknown	18:50–00:35 (marginal, 5.75 h)	79.2° 18:55	11.39	75%	19.1°
2047-01-07 Mon	21	—	unknown	18:50–00:10 (marginal, 5.33 h)	79.2° 18:50	11.37	83%	28.7°
2047-01-08 Tue	22	—	unknown	18:50–23:55 (marginal, 5.08 h)	79.2° 18:45	11.36	90%	39.9°
2047-01-09 Wed	29	—	unknown	18:50–23:55 (marginal, 5.08 h)	79.2° 18:40	11.34	95%	51.9°
2047-01-10 Thu	40	—	unknown	18:50–00:05 (marginal, 5.25 h)	79.2° 18:35	11.33	98%	64.5°
2047-01-11 Fri	57	—	unknown	18:50–21:05 (good, 2.25 h)	79.2° 18:35	11.31	100%	77.5°
2047-01-12 Sat	75	—	unknown	18:55–22:30 (good, 3.58 h)	79.2° 18:30	11.29	99%	90.8°
2047-01-13 Sun	100	—	unknown	18:55–23:35 (good, 4.67 h)	79.2° 18:25	11.27	96%	104.3°
2047-01-14 Mon	100	—	unknown	18:55–23:40 (good, 4.75 h)	79.2° 18:20	11.25	90%	117.9°
2047-01-15 Tue	100	—	unknown	18:55–23:40 (good, 4.75 h)	79.2° 18:15	11.23	82%	131.5°
2047-01-16 Wed	100	—	unknown	18:55–23:40 (good, 4.75 h)	79.2° 18:15	11.21	72%	144.7°
2047-01-17 Thu	100	—	unknown	19:00–23:40 (good, 4.67 h)	79.2° 18:10	11.18	61%	156.9°
2047-01-18 Fri	100	—	unknown	19:00–23:40 (good, 4.67 h)	79.2° 18:05	11.16	50%	165.2°
2047-01-19 Sat	100	—	unknown	19:00–23:35 (good, 4.58 h)	79.2° 18:00	11.13	39%	162.9°
2047-01-20 Sun	100	—	unknown	19:00–23:30 (good, 4.5 h)	79.2° 18:00	11.11	28%	152.6°
2047-01-21 Mon	100	—	unknown	19:00–23:25 (good, 4.42 h)	79.2° 17:55	11.08	19%	140.2°
2047-01-22 Tue	100	—	unknown	19:05–23:20 (good, 4.25 h)	79.2° 17:50	11.06	11%	127.3°
2047-01-23 Wed	100	—	unknown	19:05–23:20 (good, 4.25 h)	79.2° 17:45	11.03	5%	114.4°
2047-01-24 Thu	100	—	unknown	19:05–23:15 (good, 4.17 h)	79.2° 17:40	11.0	1%	101.5°
2047-01-25 Fri	100	—	unknown	19:05–23:10 (good, 4.08 h)	79.2° 17:40	10.98	0%	88.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-12-27&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.