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: 01-05 (43), 01-06 (37), 01-07 (31), 01-08 (27), 01-19 (24) — by astronomy; check the weather when the night is within four days.

2041-01-05astronomy score per night — click a bar for that night2041-02-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-01-05 Sat	43	—	unknown	18:45–20:40 (good, 1.92 h)	87.2° 14:20	11.4	14%	63.0°
2041-01-06 Sun	37	—	unknown	18:50–20:25 (good, 1.58 h)	87.2° 14:15	11.38	24%	62.4°
2041-01-07 Mon	31	—	unknown	18:50–20:15 (good, 1.42 h)	87.2° 14:10	11.37	34%	63.7°
2041-01-08 Tue	27	—	unknown	18:50–20:05 (good, 1.25 h)	87.2° 14:10	11.35	45%	66.5°
2041-01-09 Wed	22	—	unknown	18:50–19:50 (good, 1.0 h)	87.2° 14:05	11.34	56%	70.6°
2041-01-10 Thu	19	—	unknown	18:50–19:00 (good, 0.17 h)	87.2° 14:00	11.32	66%	75.5°
2041-01-11 Fri	17	—	unknown	18:55–20:45 (marginal, 1.83 h)	87.2° 13:55	11.3	75%	80.9°
2041-01-12 Sat	16	—	unknown	18:55–20:40 (marginal, 1.75 h)	87.2° 13:50	11.28	83%	86.6°
2041-01-13 Sun	17	—	unknown	18:20–20:35 (marginal, 2.25 h)	87.2° 13:50	11.26	90%	92.3°
2041-01-14 Mon	18	—	unknown	18:55–19:20 (good, 0.42 h)	87.2° 13:45	11.24	95%	97.9°
2041-01-15 Tue	18	—	unknown	18:55–19:30 (good, 0.58 h)	87.2° 13:40	11.22	98%	103.1°
2041-01-16 Wed	19	—	unknown	18:55–19:35 (good, 0.67 h)	87.2° 13:35	11.2	100%	107.8°
2041-01-17 Thu	19	—	unknown	19:00–19:35 (good, 0.58 h)	87.2° 13:30	11.17	100%	111.8°
2041-01-18 Fri	21	—	unknown	19:00–19:35 (good, 0.58 h)	87.2° 13:30	11.15	97%	114.9°
2041-01-19 Sat	24	—	unknown	19:00–19:35 (good, 0.58 h)	87.2° 13:25	11.12	94%	116.9°
2041-01-20 Sun	23	—	unknown	19:00–19:40 (good, 0.67 h)	87.2° 13:20	11.1	88%	117.7°
2041-01-21 Mon	21	—	unknown	19:05–19:35 (good, 0.5 h)	87.2° 13:15	11.07	82%	117.3°
2041-01-22 Tue	20	—	unknown	19:05–19:35 (good, 0.5 h)	87.2° 13:15	11.05	74%	115.5°
2041-01-23 Wed	18	—	unknown	19:05–19:30 (good, 0.42 h)	87.2° 13:10	11.02	65%	112.5°
2041-01-24 Thu	16	—	unknown	19:05–19:25 (good, 0.33 h)	87.2° 13:05	10.99	55%	108.5°
2041-01-25 Fri	15	—	unknown	19:05–19:20 (good, 0.25 h)	87.2° 13:00	10.96	45%	103.5°
2041-01-26 Sat	13	—	unknown	19:10–19:15 (good, 0.08 h)	87.2° 12:55	10.93	34%	97.8°
2041-01-27 Sun	12	—	unknown	19:10–19:15 (good, 0.08 h)	87.2° 12:55	10.9	24%	91.5°
2041-01-28 Mon	12	—	unknown	18:35–19:45 (marginal, 1.17 h)	87.2° 12:50	10.87	15%	84.9°
2041-01-29 Tue	11	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.2° 12:45	10.84	8%	78.4°
2041-01-30 Wed	10	—	unknown	19:10–19:35 (marginal, 0.42 h)	87.2° 12:40	10.81	3%	72.4°
2041-01-31 Thu	9	—	unknown	19:15–19:30 (marginal, 0.25 h)	87.2° 12:35	10.78	0%	67.3°
2041-02-01 Fri	9	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:35	10.75	1%	63.8°
2041-02-02 Sat	9	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.2° 12:30	10.71	5%	62.3°
2041-02-03 Sun	9	—	unknown	05:30–05:55 (marginal, 0.42 h)	87.2° 12:25	10.68	11%	62.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-01-05&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.