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: 03-14 (37), 03-15 (37), 03-16 (37), 03-11 (36), 03-12 (36) — by astronomy; check the weather when the night is within four days.

2030-02-17astronomy score per night — click a bar for that night2030-03-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-02-17 Sun	14	—	unknown	05:25–05:40 (good, 0.25 h)	87.2° 11:25	10.16	100%	125.8°
2030-02-18 Mon	15	—	unknown	05:20–05:40 (good, 0.33 h)	87.2° 11:25	10.12	99%	127.4°
2030-02-19 Tue	16	—	unknown	05:15–05:40 (good, 0.42 h)	87.2° 11:20	10.08	96%	126.4°
2030-02-20 Wed	17	—	unknown	05:15–05:40 (good, 0.42 h)	87.2° 11:15	10.04	91%	123.0°
2030-02-21 Thu	17	—	unknown	05:10–05:35 (good, 0.42 h)	87.2° 11:10	10.0	83%	117.4°
2030-02-22 Fri	17	—	unknown	05:05–05:35 (good, 0.5 h)	87.2° 11:10	9.95	74%	110.4°
2030-02-23 Sat	17	—	unknown	05:05–05:35 (good, 0.5 h)	87.2° 11:05	9.91	63%	102.4°
2030-02-24 Sun	18	—	unknown	05:00–05:30 (good, 0.5 h)	87.2° 11:00	9.87	52%	94.0°
2030-02-25 Mon	20	—	unknown	04:55–05:30 (good, 0.58 h)	87.2° 10:55	9.82	40%	85.5°
2030-02-26 Tue	21	—	unknown	04:45–05:30 (good, 0.75 h)	87.2° 10:50	9.78	30%	77.2°
2030-02-27 Wed	23	—	unknown	04:40–05:30 (good, 0.83 h)	87.2° 10:50	9.74	20%	69.5°
2030-02-28 Thu	26	—	unknown	04:30–05:25 (good, 0.92 h)	87.2° 10:45	9.69	12%	62.8°
2030-03-01 Fri	27	—	unknown	04:25–05:25 (good, 1.0 h)	87.2° 10:40	9.65	6%	57.5°
2030-03-02 Sat	29	—	unknown	04:20–05:25 (good, 1.08 h)	87.2° 10:35	9.6	2%	54.0°
2030-03-03 Sun	29	—	unknown	04:15–05:20 (good, 1.08 h)	87.2° 10:30	9.55	0%	52.6°
2030-03-04 Mon	29	—	unknown	04:15–05:20 (good, 1.08 h)	87.2° 10:30	9.51	1%	53.4°
2030-03-05 Tue	31	—	unknown	04:10–05:20 (good, 1.17 h)	87.2° 10:25	9.46	3%	56.3°
2030-03-06 Wed	31	—	unknown	04:05–05:15 (good, 1.17 h)	87.2° 10:20	9.41	7%	60.6°
2030-03-07 Thu	32	—	unknown	04:00–05:15 (good, 1.25 h)	87.2° 10:15	9.37	13%	66.2°
2030-03-08 Fri	33	—	unknown	04:00–05:15 (good, 1.25 h)	87.2° 10:15	9.32	20%	72.5°
2030-03-09 Sat	33	—	unknown	03:55–05:10 (good, 1.25 h)	87.2° 10:10	9.27	28%	79.3°
2030-03-10 Sun	35	—	unknown	03:50–05:10 (good, 1.33 h)	87.2° 10:05	9.22	37%	86.4°
2030-03-11 Mon	36	—	unknown	03:45–05:10 (good, 1.42 h)	87.2° 10:00	9.17	46%	93.6°
2030-03-12 Tue	36	—	unknown	03:40–05:05 (good, 1.42 h)	87.2° 09:55	9.12	56%	100.8°
2030-03-13 Wed	36	—	unknown	03:40–05:05 (good, 1.42 h)	87.2° 09:55	9.07	65%	107.8°
2030-03-14 Thu	37	—	unknown	03:40–05:05 (good, 1.42 h)	87.2° 09:50	9.02	74%	114.3°
2030-03-15 Fri	37	—	unknown	03:40–05:00 (good, 1.33 h)	87.2° 09:45	8.97	83%	120.1°
2030-03-16 Sat	37	—	unknown	03:35–05:00 (good, 1.42 h)	87.2° 09:40	8.92	90%	124.5°
2030-03-17 Sun	34	—	unknown	03:35–05:00 (good, 1.42 h)	87.2° 09:35	8.87	96%	127.1°
2030-03-18 Mon	33	—	unknown	03:30–04:55 (good, 1.42 h)	87.2° 09:35	8.82	99%	127.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-02-17&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.