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

2044-01-20astronomy score per night — click a bar for that night2044-02-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-01-20 Wed	24	—	unknown	19:00–19:45 (good, 0.75 h)	87.2° 13:25	11.12	60%	116.8°
2044-01-21 Thu	23	—	unknown	19:00–19:40 (good, 0.67 h)	87.2° 13:20	11.09	50%	112.4°
2044-01-22 Fri	21	—	unknown	19:05–19:35 (good, 0.5 h)	87.2° 13:15	11.07	41%	107.3°
2044-01-23 Sat	19	—	unknown	19:05–19:30 (good, 0.42 h)	87.2° 13:10	11.04	32%	101.6°
2044-01-24 Sun	18	—	unknown	19:05–19:30 (good, 0.42 h)	87.2° 13:10	11.01	24%	95.6°
2044-01-25 Mon	16	—	unknown	19:05–19:25 (good, 0.33 h)	87.2° 13:05	10.98	16%	89.4°
2044-01-26 Tue	15	—	unknown	19:05–19:20 (good, 0.25 h)	87.2° 13:00	10.95	10%	83.2°
2044-01-27 Wed	13	—	unknown	19:10–19:15 (good, 0.08 h)	87.2° 12:55	10.93	5%	77.2°
2044-01-28 Thu	12	—	unknown	18:35–19:45 (marginal, 1.17 h)	87.2° 12:50	10.9	2%	71.5°
2044-01-29 Fri	11	—	unknown	18:40–19:45 (marginal, 1.08 h)	87.2° 12:50	10.86	0%	66.4°
2044-01-30 Sat	11	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.2° 12:45	10.83	1%	62.3°
2044-01-31 Sun	9	—	unknown	19:15–19:35 (marginal, 0.33 h)	87.2° 12:40	10.8	3%	59.4°
2044-02-01 Mon	9	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:35	10.77	8%	58.2°
2044-02-02 Tue	9	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:30	10.74	14%	58.7°
2044-02-03 Wed	9	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.2° 12:30	10.7	22%	61.1°
2044-02-04 Thu	8	—	unknown	05:30–05:55 (marginal, 0.42 h)	87.2° 12:25	10.67	32%	65.2°
2044-02-05 Fri	9	—	unknown	05:25–05:55 (marginal, 0.5 h)	87.2° 12:20	10.63	43%	70.6°
2044-02-06 Sat	9	—	unknown	05:20–06:30 (marginal, 1.17 h)	87.2° 12:15	10.6	54%	77.1°
2044-02-07 Sun	9	—	unknown	05:20–06:25 (marginal, 1.08 h)	87.2° 12:15	10.56	65%	84.3°
2044-02-08 Mon	10	—	unknown	05:50–05:55 (good, 0.08 h)	87.2° 12:10	10.53	76%	91.9°
2044-02-09 Tue	10	—	unknown	05:45–05:50 (good, 0.08 h)	87.2° 12:05	10.49	85%	99.4°
2044-02-10 Wed	9	—	unknown	05:05–05:50 (marginal, 0.75 h)	87.2° 12:00	10.45	92%	106.6°
2044-02-11 Thu	9	—	unknown	05:05–06:20 (marginal, 1.25 h)	87.2° 11:55	10.42	98%	112.8°
2044-02-12 Fri	10	—	unknown	05:45–05:50 (good, 0.08 h)	87.2° 11:50	10.38	100%	117.7°
2044-02-13 Sat	11	—	unknown	05:45–05:50 (good, 0.08 h)	87.2° 11:45	10.34	99%	120.8°
2044-02-14 Sun	11	—	unknown	05:40–05:45 (good, 0.08 h)	87.2° 11:40	10.3	96%	121.9°
2044-02-15 Mon	12	—	unknown	05:35–05:45 (good, 0.17 h)	87.2° 11:35	10.26	92%	121.0°
2044-02-16 Tue	13	—	unknown	05:30–05:45 (good, 0.25 h)	87.2° 11:35	10.22	85%	118.3°
2044-02-17 Wed	14	—	unknown	05:25–05:45 (good, 0.33 h)	87.2° 11:30	10.18	77%	114.3°
2044-02-18 Thu	14	—	unknown	05:25–05:40 (good, 0.25 h)	87.2° 11:25	10.14	68%	109.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-01-20&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.