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: 01-10 (93), 01-11 (93), 01-12 (93), 01-13 (93), 01-14 (93) — by astronomy; check the weather when the night is within four days.

2030-01-10astronomy score per night — click a bar for that night2030-02-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-01-10 Thu	93	—	unknown	01:40–06:10 (good, 4.5 h)	50.2° 05:30	11.32	44%	167.6°
2030-01-11 Fri	93	—	unknown	01:40–06:10 (good, 4.5 h)	50.2° 05:25	11.3	53%	158.3°
2030-01-12 Sat	93	—	unknown	01:40–06:10 (good, 4.5 h)	50.2° 05:20	11.29	63%	147.3°
2030-01-13 Sun	93	—	unknown	01:35–06:10 (good, 4.58 h)	50.2° 05:15	11.27	71%	136.0°
2030-01-14 Mon	93	—	unknown	01:35–06:10 (good, 4.58 h)	50.2° 05:15	11.25	80%	124.4°
2030-01-15 Tue	93	—	unknown	01:35–06:10 (good, 4.58 h)	50.2° 05:10	11.22	87%	112.6°
2030-01-16 Wed	93	—	unknown	01:45–06:10 (good, 4.42 h)	50.2° 05:05	11.2	93%	100.6°
2030-01-17 Thu	65	—	unknown	02:50–06:10 (good, 3.33 h)	50.2° 05:00	11.18	97%	88.3°
2030-01-18 Fri	51	—	unknown	04:25–06:10 (good, 1.75 h)	50.2° 04:55	11.16	99%	75.8°
2030-01-19 Sat	38	—	unknown	01:15–06:10 (marginal, 4.92 h)	50.2° 04:55	11.13	100%	63.1°
2030-01-20 Sun	28	—	unknown	01:25–06:10 (marginal, 4.75 h)	50.2° 04:50	11.11	98%	50.2°
2030-01-21 Mon	22	—	unknown	01:50–06:05 (marginal, 4.25 h)	50.2° 04:45	11.08	94%	37.2°
2030-01-22 Tue	22	—	unknown	01:15–06:05 (marginal, 4.83 h)	50.2° 04:40	11.05	88%	24.4°
2030-01-23 Wed	28	—	unknown	00:45–06:05 (marginal, 5.33 h)	50.2° 04:40	11.03	80%	13.1°
2030-01-24 Thu	38	—	unknown	00:25–06:05 (marginal, 5.67 h)	50.2° 04:35	11.0	70%	11.1°
2030-01-25 Fri	54	—	unknown	02:20–04:30 (good, 2.17 h)	50.2° 04:30	10.97	59%	21.5°
2030-01-26 Sat	83	—	unknown	00:40–06:05 (good, 5.42 h)	50.2° 04:25	10.94	48%	34.5°
2030-01-27 Sun	90	—	unknown	00:35–06:05 (good, 5.5 h)	50.2° 04:20	10.91	37%	48.2°
2030-01-28 Mon	93	—	unknown	00:30–06:05 (good, 5.58 h)	50.2° 04:20	10.88	26%	62.1°
2030-01-29 Tue	93	—	unknown	00:25–06:00 (good, 5.58 h)	50.2° 04:15	10.85	17%	76.0°
2030-01-30 Wed	93	—	unknown	00:25–06:00 (good, 5.58 h)	50.2° 04:10	10.82	9%	90.0°
2030-01-31 Thu	93	—	unknown	00:20–06:00 (good, 5.67 h)	50.2° 04:05	10.79	4%	103.8°
2030-02-01 Fri	93	—	unknown	00:15–06:00 (good, 5.75 h)	50.2° 04:00	10.76	1%	117.5°
2030-02-02 Sat	93	—	unknown	00:10–06:00 (good, 5.83 h)	50.2° 04:00	10.72	0%	130.8°
2030-02-03 Sun	93	—	unknown	00:10–06:00 (good, 5.83 h)	50.2° 03:55	10.69	2%	143.8°
2030-02-04 Mon	93	—	unknown	00:05–05:55 (good, 5.83 h)	50.2° 03:50	10.65	6%	156.0°
2030-02-05 Tue	93	—	unknown	00:00–05:55 (good, 5.92 h)	50.2° 03:45	10.62	12%	166.5°
2030-02-06 Wed	93	—	unknown	23:55–05:55 (good, 6.0 h)	50.2° 03:45	10.58	19%	169.7°
2030-02-07 Thu	93	—	unknown	23:50–05:55 (good, 6.08 h)	50.2° 03:40	10.55	27%	161.9°
2030-02-08 Fri	93	—	unknown	23:50–05:55 (good, 6.08 h)	50.2° 03:35	10.51	36%	151.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-01-10&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.