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: 04-03 (54), 03-31 (52), 04-01 (52), 04-02 (52), 03-30 (51) — by astronomy; check the weather when the night is within four days.

2038-03-05astronomy score per night — click a bar for that night2038-04-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-03-05 Fri	31	—	unknown	04:10–05:20 (good, 1.17 h)	87.2° 10:25	9.46	0%	61.9°
2038-03-06 Sat	31	—	unknown	04:05–05:15 (good, 1.17 h)	87.2° 10:20	9.41	1%	63.9°
2038-03-07 Sun	32	—	unknown	04:00–05:15 (good, 1.25 h)	87.2° 10:15	9.36	4%	66.9°
2038-03-08 Mon	34	—	unknown	04:00–05:15 (good, 1.25 h)	87.2° 10:15	9.32	8%	70.9°
2038-03-09 Tue	33	—	unknown	03:55–05:10 (good, 1.25 h)	87.2° 10:10	9.27	14%	75.7°
2038-03-10 Wed	34	—	unknown	03:50–05:10 (good, 1.33 h)	87.2° 10:05	9.22	21%	80.9°
2038-03-11 Thu	36	—	unknown	03:45–05:10 (good, 1.42 h)	87.2° 10:00	9.17	29%	86.5°
2038-03-12 Fri	36	—	unknown	03:40–05:05 (good, 1.42 h)	87.2° 09:55	9.12	38%	92.2°
2038-03-13 Sat	36	—	unknown	03:40–05:05 (good, 1.42 h)	87.2° 09:55	9.07	48%	98.1°
2038-03-14 Sun	38	—	unknown	03:35–05:05 (good, 1.5 h)	87.2° 09:50	9.02	58%	103.7°
2038-03-15 Mon	38	—	unknown	03:30–05:00 (good, 1.5 h)	87.2° 09:45	8.97	68%	108.9°
2038-03-16 Tue	38	—	unknown	03:35–05:00 (good, 1.42 h)	87.2° 09:40	8.92	78%	113.4°
2038-03-17 Wed	35	—	unknown	03:35–05:00 (good, 1.42 h)	87.2° 09:35	8.87	86%	116.8°
2038-03-18 Thu	33	—	unknown	03:30–04:55 (good, 1.42 h)	87.2° 09:35	8.82	93%	118.5°
2038-03-19 Fri	33	—	unknown	03:30–04:55 (good, 1.42 h)	87.2° 09:30	8.77	98%	118.2°
2038-03-20 Sat	32	—	unknown	03:30–04:50 (good, 1.33 h)	87.2° 09:25	8.72	100%	115.9°
2038-03-21 Sun	31	—	unknown	03:30–04:50 (good, 1.33 h)	87.2° 09:20	8.67	99%	111.7°
2038-03-22 Mon	29	—	unknown	03:25–04:50 (good, 1.42 h)	87.2° 09:20	8.61	95%	106.1°
2038-03-23 Tue	28	—	unknown	03:25–04:45 (good, 1.33 h)	87.2° 09:15	8.56	88%	99.6°
2038-03-24 Wed	29	—	unknown	03:20–04:45 (good, 1.42 h)	87.2° 09:10	8.51	79%	92.7°
2038-03-25 Thu	30	—	unknown	03:15–04:45 (good, 1.5 h)	87.2° 09:05	8.46	69%	85.9°
2038-03-26 Fri	32	—	unknown	03:05–04:40 (good, 1.58 h)	87.2° 09:00	8.4	59%	79.5°
2038-03-27 Sat	35	—	unknown	04:00–05:40 (good, 1.67 h)	87.2° 10:00	8.35	48%	73.8°
2038-03-28 Sun	39	—	unknown	03:40–05:35 (good, 1.92 h)	87.2° 09:55	8.3	38%	68.9°
2038-03-29 Mon	46	—	unknown	03:35–05:35 (good, 2.0 h)	87.2° 09:50	8.24	28%	65.2°
2038-03-30 Tue	51	—	unknown	03:30–05:35 (good, 2.08 h)	87.2° 09:45	8.19	20%	62.6°
2038-03-31 Wed	52	—	unknown	03:25–05:30 (good, 2.08 h)	87.2° 09:40	8.13	12%	61.5°
2038-04-01 Thu	52	—	unknown	03:25–05:30 (good, 2.08 h)	87.2° 09:40	8.08	7%	61.7°
2038-04-02 Fri	52	—	unknown	03:20–05:25 (good, 2.08 h)	87.2° 09:35	8.02	3%	63.3°
2038-04-03 Sat	54	—	unknown	03:15–05:25 (good, 2.17 h)	87.2° 09:30	7.97	1%	66.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-03-05&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.