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 3C 273: 01-09 (93), 01-10 (93), 01-11 (93), 01-12 (93), 01-13 (93) — by astronomy; check the weather when the night is within four days.

2031-12-31astronomy score per night — click a bar for that night2032-01-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-12-31 Wed	23	—	unknown	02:30–06:10 (marginal, 3.67 h)	50.2° 06:10	11.46	91%	51.8°
2032-01-01 Thu	20	—	unknown	02:30–06:10 (marginal, 3.67 h)	50.2° 06:05	11.45	85%	40.2°
2032-01-02 Fri	21	—	unknown	02:20–06:10 (marginal, 3.83 h)	50.2° 06:00	11.44	77%	28.7°
2032-01-03 Sat	27	—	unknown	02:00–06:10 (marginal, 4.17 h)	50.2° 06:00	11.43	69%	17.6°
2032-01-04 Sun	36	—	unknown	01:45–06:10 (marginal, 4.42 h)	50.2° 05:55	11.42	60%	8.9°
2032-01-05 Mon	47	—	unknown	02:50–06:10 (good, 3.33 h)	50.2° 05:50	11.41	50%	12.0°
2032-01-06 Tue	60	—	unknown	02:20–06:10 (good, 3.83 h)	50.2° 05:45	11.39	40%	23.1°
2032-01-07 Wed	79	—	unknown	01:55–06:10 (good, 4.25 h)	50.2° 05:45	11.38	30%	35.7°
2032-01-08 Thu	90	—	unknown	01:50–06:10 (good, 4.33 h)	50.2° 05:40	11.36	20%	49.0°
2032-01-09 Fri	93	—	unknown	01:50–06:10 (good, 4.33 h)	50.2° 05:35	11.35	12%	63.0°
2032-01-10 Sat	93	—	unknown	01:45–06:10 (good, 4.42 h)	50.2° 05:30	11.33	5%	77.4°
2032-01-11 Sun	93	—	unknown	01:40–06:10 (good, 4.5 h)	50.2° 05:25	11.31	1%	92.2°
2032-01-12 Mon	93	—	unknown	01:35–06:10 (good, 4.58 h)	50.2° 05:25	11.3	0%	107.3°
2032-01-13 Tue	93	—	unknown	01:30–06:10 (good, 4.67 h)	50.2° 05:20	11.28	2%	122.4°
2032-01-14 Wed	93	—	unknown	01:30–06:10 (good, 4.67 h)	50.2° 05:15	11.26	7%	137.3°
2032-01-15 Thu	93	—	unknown	01:25–06:10 (good, 4.75 h)	50.2° 05:10	11.23	14%	151.7°
2032-01-16 Fri	93	—	unknown	01:20–06:10 (good, 4.83 h)	50.2° 05:05	11.21	23%	165.0°
2032-01-17 Sat	93	—	unknown	01:15–06:10 (good, 4.92 h)	50.2° 05:05	11.19	33%	171.9°
2032-01-18 Sun	93	—	unknown	01:15–06:10 (good, 4.92 h)	50.2° 05:00	11.17	44%	163.0°
2032-01-19 Mon	93	—	unknown	01:15–06:10 (good, 4.92 h)	50.2° 04:55	11.14	55%	150.8°
2032-01-20 Tue	93	—	unknown	01:10–06:10 (good, 5.0 h)	50.2° 04:50	11.12	65%	138.3°
2032-01-21 Wed	93	—	unknown	01:10–06:05 (good, 4.92 h)	50.2° 04:50	11.09	74%	126.0°
2032-01-22 Thu	93	—	unknown	01:10–06:05 (good, 4.92 h)	50.2° 04:45	11.07	82%	113.9°
2032-01-23 Fri	93	—	unknown	01:15–06:05 (good, 4.83 h)	50.2° 04:40	11.04	89%	101.9°
2032-01-24 Sat	91	—	unknown	02:00–06:05 (good, 4.08 h)	50.2° 04:35	11.01	94%	90.0°
2032-01-25 Sun	61	—	unknown	03:25–06:05 (good, 2.67 h)	50.2° 04:30	10.99	98%	78.2°
2032-01-26 Mon	46	—	unknown	05:30–06:05 (good, 0.58 h)	50.2° 04:30	10.96	100%	66.4°
2032-01-27 Tue	35	—	unknown	00:55–06:05 (marginal, 5.17 h)	50.2° 04:25	10.93	100%	54.8°
2032-01-28 Wed	26	—	unknown	01:25–06:05 (marginal, 4.67 h)	50.2° 04:20	10.9	98%	43.1°
2032-01-29 Thu	20	—	unknown	02:45–06:00 (marginal, 3.25 h)	50.2° 04:15	10.87	95%	31.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-12-31&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.