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: 01-20 (24), 01-21 (23), 01-22 (20), 01-23 (19), 01-24 (18) — by astronomy; check the weather when the night is within four days.

2047-01-20astronomy score per night — click a bar for that night2047-02-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2047-02-08 Fri	9	—	unknown	05:15–05:55 (marginal, 0.67 h)	87.1° 12:10	10.52	96%	114.1°
2047-02-09 Sat	9	—	unknown	05:10–05:50 (marginal, 0.67 h)	87.2° 12:00	10.48	99%	120.0°
2047-02-10 Sun	9	—	unknown	05:05–06:25 (marginal, 1.33 h)	87.2° 12:00	10.44	100%	124.3°
2047-02-11 Mon	10	—	unknown	05:00–06:20 (marginal, 1.33 h)	87.2° 11:50	10.41	98%	126.2°
2047-02-12 Tue	10	—	unknown	05:45–05:50 (good, 0.08 h)	87.2° 11:50	10.37	92%	125.5°
2047-02-13 Wed	11	—	unknown	05:40–05:45 (good, 0.08 h)	87.2° 11:45	10.33	85%	122.2°
2047-02-14 Thu	12	—	unknown	05:35–05:45 (good, 0.17 h)	87.2° 11:40	10.29	76%	116.8°
2047-02-15 Fri	12	—	unknown	05:35–05:45 (good, 0.17 h)	87.2° 11:35	10.25	65%	109.9°
2047-02-16 Sat	14	—	unknown	05:30–05:45 (good, 0.25 h)	87.1° 11:30	10.21	54%	102.2°
2047-02-17 Sun	14	—	unknown	05:25–05:40 (good, 0.25 h)	87.2° 11:30	10.17	43%	94.2°
2047-02-18 Mon	15	—	unknown	05:20–05:40 (good, 0.33 h)	87.2° 11:25	10.13	32%	86.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-01-20&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.