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.

2035-12-27astronomy score per night — click a bar for that night2036-01-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-12-27 Thu	100	—	unknown	18:40–01:05 (good, 6.42 h)	79.1° 19:35	11.49	3%	130.0°
2035-12-28 Fri	100	—	unknown	18:40–01:00 (good, 6.33 h)	79.1° 19:30	11.49	0%	119.7°
2035-12-29 Sat	100	—	unknown	18:40–00:55 (good, 6.25 h)	79.2° 19:25	11.48	0%	109.1°
2035-12-30 Sun	100	—	unknown	18:40–00:55 (good, 6.25 h)	79.1° 19:20	11.47	2%	98.3°
2035-12-31 Mon	100	—	unknown	18:45–00:50 (good, 6.08 h)	79.1° 19:15	11.46	5%	87.5°
2036-01-01 Tue	100	—	unknown	18:45–00:45 (good, 6.0 h)	79.1° 19:15	11.45	10%	76.7°
2036-01-02 Wed	100	—	unknown	18:45–00:40 (good, 5.92 h)	79.1° 19:10	11.44	16%	65.9°
2036-01-03 Thu	98	—	unknown	18:45–00:40 (good, 5.92 h)	79.2° 19:05	11.43	23%	55.3°
2036-01-04 Fri	90	—	unknown	18:45–00:35 (good, 5.83 h)	79.1° 19:00	11.42	32%	44.9°
2036-01-05 Sat	82	—	unknown	18:45–00:30 (good, 5.75 h)	79.1° 18:55	11.41	42%	35.3°
2036-01-06 Sun	67	—	unknown	18:45–00:00 (good, 5.25 h)	79.1° 18:55	11.39	52%	27.6°
2036-01-07 Mon	48	—	unknown	18:50–00:45 (marginal, 5.92 h)	79.2° 18:50	11.38	62%	24.1°
2036-01-08 Tue	33	—	unknown	18:50–00:30 (marginal, 5.67 h)	79.2° 18:45	11.36	73%	27.3°
2036-01-09 Wed	27	—	unknown	18:50–00:10 (marginal, 5.33 h)	79.1° 18:40	11.35	82%	35.8°
2036-01-10 Thu	29	—	unknown	18:50–00:00 (marginal, 5.17 h)	79.1° 18:40	11.33	90%	47.2°
2036-01-11 Fri	37	—	unknown	18:50–00:00 (marginal, 5.17 h)	79.1° 18:35	11.31	96%	60.1°
2036-01-12 Sat	51	—	unknown	18:55–20:20 (good, 1.42 h)	79.2° 18:30	11.29	100%	73.8°
2036-01-13 Sun	69	—	unknown	18:55–22:05 (good, 3.17 h)	79.1° 18:25	11.28	100%	87.7°
2036-01-14 Mon	86	—	unknown	18:55–23:25 (good, 4.5 h)	79.1° 18:20	11.26	97%	101.6°
2036-01-15 Tue	100	—	unknown	18:55–23:35 (good, 4.67 h)	79.1° 18:20	11.23	91%	115.1°
2036-01-16 Wed	100	—	unknown	18:55–23:40 (good, 4.75 h)	79.1° 18:15	11.21	83%	127.8°
2036-01-17 Thu	100	—	unknown	19:00–23:35 (good, 4.58 h)	79.2° 18:10	11.19	74%	139.4°
2036-01-18 Fri	100	—	unknown	19:00–23:35 (good, 4.58 h)	79.1° 18:05	11.17	64%	149.0°
2036-01-19 Sat	100	—	unknown	19:00–23:35 (good, 4.58 h)	79.1° 18:00	11.14	54%	154.9°
2036-01-20 Sun	100	—	unknown	19:00–23:30 (good, 4.5 h)	79.1° 18:00	11.12	43%	155.2°
2036-01-21 Mon	100	—	unknown	19:00–23:25 (good, 4.42 h)	79.2° 17:55	11.09	34%	150.1°
2036-01-22 Tue	100	—	unknown	19:05–23:25 (good, 4.33 h)	79.2° 17:50	11.07	25%	141.9°
2036-01-23 Wed	100	—	unknown	19:05–23:20 (good, 4.25 h)	79.1° 17:45	11.04	17%	132.4°
2036-01-24 Thu	100	—	unknown	19:05–23:15 (good, 4.17 h)	79.1° 17:45	11.01	11%	122.2°
2036-01-25 Fri	100	—	unknown	19:05–23:10 (good, 4.08 h)	79.1° 17:40	10.98	6%	111.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-12-27&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.