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: 01-06 (93), 01-07 (93), 01-21 (93), 01-22 (93), 01-23 (93) — by astronomy; check the weather when the night is within four days.

2047-01-06astronomy score per night — click a bar for that night2047-02-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-01-06 Sun	93	—	unknown	02:05–06:10 (good, 4.08 h)	50.1° 05:45	11.39	75%	138.7°
2047-01-07 Mon	93	—	unknown	02:05–06:10 (good, 4.08 h)	50.1° 05:40	11.37	83%	126.8°
2047-01-08 Tue	92	—	unknown	02:05–06:10 (good, 4.08 h)	50.1° 05:40	11.36	90%	114.6°
2047-01-09 Wed	71	—	unknown	02:15–06:10 (good, 3.92 h)	50.1° 05:35	11.34	95%	102.0°
2047-01-10 Thu	58	—	unknown	03:20–06:10 (good, 2.83 h)	50.1° 05:30	11.33	98%	89.0°
2047-01-11 Fri	44	—	unknown	05:05–06:10 (good, 1.08 h)	50.1° 05:25	11.31	100%	75.8°
2047-01-12 Sat	32	—	unknown	01:45–06:10 (marginal, 4.42 h)	50.1° 05:20	11.29	99%	62.3°
2047-01-13 Sun	24	—	unknown	01:55–06:10 (marginal, 4.25 h)	50.1° 05:20	11.27	96%	48.6°
2047-01-14 Mon	20	—	unknown	01:55–06:10 (marginal, 4.25 h)	50.1° 05:15	11.25	90%	35.0°
2047-01-15 Tue	23	—	unknown	01:30–06:10 (marginal, 4.67 h)	50.1° 05:10	11.23	82%	21.8°
2047-01-16 Wed	32	—	unknown	01:05–06:10 (marginal, 5.08 h)	50.1° 05:05	11.21	72%	11.1°
2047-01-17 Thu	44	—	unknown	00:50–06:10 (marginal, 5.33 h)	50.1° 05:05	11.18	61%	13.2°
2047-01-18 Fri	60	—	unknown	01:35–06:10 (good, 4.58 h)	50.1° 05:00	11.16	50%	24.9°
2047-01-19 Sat	85	—	unknown	01:10–06:10 (good, 5.0 h)	50.1° 04:55	11.13	39%	38.2°
2047-01-20 Sun	91	—	unknown	01:05–06:10 (good, 5.08 h)	50.1° 04:50	11.11	28%	51.8°
2047-01-21 Mon	93	—	unknown	01:00–06:05 (good, 5.08 h)	50.1° 04:45	11.08	19%	65.3°
2047-01-22 Tue	93	—	unknown	00:55–06:05 (good, 5.17 h)	50.1° 04:45	11.06	11%	78.8°
2047-01-23 Wed	93	—	unknown	00:55–06:05 (good, 5.17 h)	50.1° 04:40	11.03	5%	92.2°
2047-01-24 Thu	93	—	unknown	00:50–06:05 (good, 5.25 h)	50.1° 04:35	11.0	1%	105.3°
2047-01-25 Fri	93	—	unknown	00:45–06:05 (good, 5.33 h)	50.1° 04:30	10.98	0%	118.2°
2047-01-26 Sat	93	—	unknown	00:40–06:05 (good, 5.42 h)	50.1° 04:25	10.95	1%	130.8°
2047-01-27 Sun	93	—	unknown	00:35–06:05 (good, 5.5 h)	50.1° 04:25	10.92	4%	143.0°
2047-01-28 Mon	93	—	unknown	00:35–06:05 (good, 5.5 h)	50.1° 04:20	10.89	8%	154.7°
2047-01-29 Tue	93	—	unknown	00:30–06:00 (good, 5.5 h)	50.1° 04:15	10.86	14%	165.1°
2047-01-30 Wed	93	—	unknown	00:25–06:00 (good, 5.58 h)	50.1° 04:10	10.82	22%	170.2°
2047-01-31 Thu	93	—	unknown	00:20–06:00 (good, 5.67 h)	50.1° 04:10	10.79	30%	164.2°
2047-02-01 Fri	93	—	unknown	00:15–06:00 (good, 5.75 h)	50.1° 04:05	10.76	39%	153.9°
2047-02-02 Sat	93	—	unknown	00:15–06:00 (good, 5.75 h)	50.1° 04:00	10.73	48%	142.7°
2047-02-03 Sun	93	—	unknown	00:15–06:00 (good, 5.75 h)	50.1° 03:55	10.69	58%	131.1°
2047-02-04 Mon	93	—	unknown	00:15–05:55 (good, 5.67 h)	50.1° 03:50	10.66	67%	119.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-01-06&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.