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: 03-12 (32), 03-11 (30), 03-10 (27), 03-09 (26), 02-25 (25) — by astronomy; check the weather when the night is within four days.

2045-02-11astronomy score per night — click a bar for that night2045-03-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-02-11 Sat	12	—	unknown	05:40–05:50 (good, 0.17 h)	87.2° 11:50	10.39	21%	83.8°
2045-02-12 Sun	13	—	unknown	05:30–05:50 (good, 0.33 h)	87.2° 11:45	10.35	14%	77.4°
2045-02-13 Mon	14	—	unknown	05:25–05:45 (good, 0.33 h)	87.2° 11:40	10.31	8%	71.5°
2045-02-14 Tue	15	—	unknown	05:25–05:45 (good, 0.33 h)	87.2° 11:40	10.27	4%	66.2°
2045-02-15 Wed	16	—	unknown	05:20–05:45 (good, 0.42 h)	87.2° 11:35	10.23	1%	61.8°
2045-02-16 Thu	18	—	unknown	05:15–05:45 (good, 0.5 h)	87.2° 11:30	10.19	0%	58.5°
2045-02-17 Fri	18	—	unknown	05:10–05:40 (good, 0.5 h)	87.2° 11:25	10.15	1%	56.7°
2045-02-18 Sat	19	—	unknown	05:05–05:40 (good, 0.58 h)	87.1° 11:25	10.11	4%	56.6°
2045-02-19 Sun	20	—	unknown	05:05–05:40 (good, 0.58 h)	87.2° 11:20	10.07	8%	58.1°
2045-02-20 Mon	21	—	unknown	05:00–05:40 (good, 0.67 h)	87.2° 11:15	10.02	14%	61.3°
2045-02-21 Tue	22	—	unknown	04:55–05:35 (good, 0.67 h)	87.2° 11:10	9.98	22%	66.0°
2045-02-22 Wed	22	—	unknown	04:50–05:35 (good, 0.75 h)	87.2° 11:05	9.94	32%	71.8°
2045-02-23 Thu	23	—	unknown	04:50–05:35 (good, 0.75 h)	87.2° 11:05	9.9	42%	78.5°
2045-02-24 Fri	23	—	unknown	04:45–05:30 (good, 0.75 h)	87.2° 11:00	9.85	53%	85.8°
2045-02-25 Sat	25	—	unknown	04:40–05:30 (good, 0.83 h)	87.2° 10:55	9.81	64%	93.5°
2045-02-26 Sun	25	—	unknown	04:35–05:30 (good, 0.92 h)	87.2° 10:50	9.76	74%	101.2°
2045-02-27 Mon	24	—	unknown	04:45–05:25 (good, 0.67 h)	87.2° 10:45	9.72	84%	108.6°
2045-02-28 Tue	22	—	unknown	04:40–05:25 (good, 0.75 h)	87.2° 10:45	9.67	92%	115.1°
2045-03-01 Wed	23	—	unknown	04:35–05:25 (good, 0.83 h)	87.2° 10:40	9.63	97%	120.1°
2045-03-02 Thu	23	—	unknown	04:35–05:25 (good, 0.83 h)	87.2° 10:35	9.58	100%	123.0°
2045-03-03 Fri	23	—	unknown	04:30–05:20 (good, 0.83 h)	87.2° 10:30	9.54	99%	123.5°
2045-03-04 Sat	24	—	unknown	04:25–05:20 (good, 0.92 h)	87.1° 10:25	9.49	96%	121.5°
2045-03-05 Sun	24	—	unknown	04:20–05:20 (good, 1.0 h)	87.2° 10:25	9.44	91%	117.5°
2045-03-06 Mon	24	—	unknown	04:20–05:15 (good, 0.92 h)	87.2° 10:20	9.4	84%	112.1°
2045-03-07 Tue	24	—	unknown	04:15–05:15 (good, 1.0 h)	87.2° 10:15	9.35	75%	105.9°
2045-03-08 Wed	25	—	unknown	04:10–05:15 (good, 1.08 h)	87.2° 10:10	9.3	66%	99.2°
2045-03-09 Thu	26	—	unknown	04:05–05:10 (good, 1.08 h)	87.2° 10:10	9.25	56%	92.4°
2045-03-10 Fri	27	—	unknown	04:00–05:10 (good, 1.17 h)	87.2° 10:05	9.2	46%	85.7°
2045-03-11 Sat	30	—	unknown	03:55–05:10 (good, 1.25 h)	87.2° 10:00	9.16	37%	79.2°
2045-03-12 Sun	32	—	unknown	03:40–05:05 (good, 1.42 h)	87.2° 09:55	9.11	28%	73.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-02-11&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.