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 North America Nebula: 01-13 (32), 01-14 (32), 01-15 (30), 01-16 (29), 01-12 (28) — by astronomy; check the weather when the night is within four days.

2047-01-09astronomy score per night — click a bar for that night2047-02-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-01-09 Wed	22	—	unknown	18:50–19:20 (good, 0.5 h)	87.2° 14:05	11.34	95%	95.2°
2047-01-10 Thu	23	—	unknown	18:50–19:50 (good, 1.0 h)	87.2° 14:00	11.33	98%	102.8°
2047-01-11 Fri	26	—	unknown	18:50–19:55 (good, 1.08 h)	87.2° 14:00	11.31	100%	110.1°
2047-01-12 Sat	28	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:55	11.29	99%	116.6°
2047-01-13 Sun	32	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:50	11.27	96%	121.9°
2047-01-14 Mon	32	—	unknown	18:55–20:05 (good, 1.17 h)	87.2° 13:45	11.25	90%	125.3°
2047-01-15 Tue	30	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:40	11.23	82%	126.3°
2047-01-16 Wed	29	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:40	11.21	72%	124.8°
2047-01-17 Thu	27	—	unknown	19:00–19:55 (good, 0.92 h)	87.2° 13:35	11.18	61%	121.0°
2047-01-18 Fri	26	—	unknown	19:00–19:50 (good, 0.83 h)	87.2° 13:30	11.16	50%	115.3°
2047-01-19 Sat	25	—	unknown	19:00–19:45 (good, 0.75 h)	87.2° 13:25	11.13	39%	108.3°
2047-01-20 Sun	24	—	unknown	19:00–19:45 (good, 0.75 h)	87.1° 13:20	11.11	28%	100.5°
2047-01-21 Mon	23	—	unknown	19:00–19:40 (good, 0.67 h)	87.2° 13:20	11.08	19%	92.4°
2047-01-22 Tue	20	—	unknown	19:05–19:35 (good, 0.5 h)	87.2° 13:15	11.06	11%	84.3°
2047-01-23 Wed	19	—	unknown	19:05–19:30 (good, 0.42 h)	87.2° 13:10	11.03	5%	76.5°
2047-01-24 Thu	18	—	unknown	19:05–19:25 (good, 0.33 h)	87.2° 13:05	11.0	1%	69.4°
2047-01-25 Fri	16	—	unknown	19:05–19:25 (good, 0.33 h)	87.1° 13:05	10.98	0%	63.2°
2047-01-26 Sat	14	—	unknown	19:10–19:20 (good, 0.17 h)	87.2° 13:00	10.95	1%	58.3°
2047-01-27 Sun	13	—	unknown	19:10–19:15 (good, 0.08 h)	87.2° 12:55	10.92	4%	55.1°
2047-01-28 Mon	12	—	unknown	18:35–19:45 (marginal, 1.17 h)	87.2° 12:50	10.89	8%	53.7°
2047-01-29 Tue	10	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.2° 12:45	10.86	14%	54.2°
2047-01-30 Wed	9	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.2° 12:45	10.82	22%	56.6°
2047-01-31 Thu	8	—	unknown	19:15–19:35 (marginal, 0.33 h)	87.2° 12:40	10.79	30%	60.4°
2047-02-01 Fri	8	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:35	10.76	39%	65.4°
2047-02-02 Sat	8	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.2° 12:30	10.73	48%	71.2°
2047-02-03 Sun	8	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.1° 12:25	10.69	58%	77.8°
2047-02-04 Mon	8	—	unknown	05:30–05:55 (marginal, 0.42 h)	87.2° 12:25	10.66	67%	84.9°
2047-02-05 Tue	9	—	unknown	05:25–05:55 (marginal, 0.5 h)	87.2° 12:20	10.62	76%	92.2°
2047-02-06 Wed	9	—	unknown	05:20–06:25 (marginal, 1.08 h)	87.2° 12:15	10.59	84%	99.8°
2047-02-07 Thu	10	—	unknown	05:50–05:55 (good, 0.08 h)	87.2° 12:10	10.55	91%	107.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-01-09&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.