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 Triangulum Pinwheel: 02-18 (48), 02-19 (48), 02-20 (46), 02-16 (44), 02-21 (44) — by astronomy; check the weather when the night is within four days.

2041-02-06astronomy score per night — click a bar for that night2041-03-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-02-06 Wed	43	—	unknown	19:20–22:00 (good, 2.67 h)	79.2° 16:50	10.57	39%	20.8°
2041-02-07 Thu	32	—	unknown	19:20–20:00 (good, 0.67 h)	79.2° 16:45	10.54	50%	24.9°
2041-02-08 Fri	24	—	unknown	19:20–22:30 (marginal, 3.17 h)	79.2° 16:40	10.5	60%	33.4°
2041-02-09 Sat	20	—	unknown	19:25–22:20 (marginal, 2.92 h)	79.2° 16:35	10.46	69%	43.5°
2041-02-10 Sun	19	—	unknown	19:25–22:10 (marginal, 2.75 h)	79.2° 16:35	10.43	78%	54.3°
2041-02-11 Mon	20	—	unknown	19:25–22:10 (marginal, 2.75 h)	79.2° 16:30	10.39	85%	65.3°
2041-02-12 Tue	24	—	unknown	19:25–22:10 (marginal, 2.75 h)	79.2° 16:25	10.35	91%	76.3°
2041-02-13 Wed	27	—	unknown	19:30–20:05 (good, 0.58 h)	79.2° 16:20	10.31	96%	87.4°
2041-02-14 Thu	33	—	unknown	19:30–21:00 (good, 1.5 h)	79.2° 16:15	10.27	99%	98.5°
2041-02-15 Fri	39	—	unknown	19:30–21:25 (good, 1.92 h)	79.2° 16:15	10.23	100%	109.5°
2041-02-16 Sat	44	—	unknown	19:30–21:30 (good, 2.0 h)	79.2° 16:10	10.19	99%	120.4°
2041-02-17 Sun	43	—	unknown	19:35–21:30 (good, 1.92 h)	79.2° 16:05	10.15	97%	131.2°
2041-02-18 Mon	48	—	unknown	19:35–21:25 (good, 1.83 h)	79.2° 16:00	10.11	93%	141.5°
2041-02-19 Tue	48	—	unknown	19:35–21:25 (good, 1.83 h)	79.2° 16:00	10.07	87%	150.8°
2041-02-20 Wed	46	—	unknown	19:35–21:25 (good, 1.83 h)	79.2° 15:55	10.03	80%	157.7°
2041-02-21 Thu	44	—	unknown	19:35–21:20 (good, 1.75 h)	79.2° 15:50	9.98	71%	159.1°
2041-02-22 Fri	41	—	unknown	19:40–21:20 (good, 1.67 h)	79.2° 15:45	9.94	61%	153.8°
2041-02-23 Sat	40	—	unknown	19:40–21:15 (good, 1.58 h)	79.2° 15:40	9.9	51%	144.4°
2041-02-24 Sun	38	—	unknown	19:40–21:10 (good, 1.5 h)	79.2° 15:40	9.85	40%	133.0°
2041-02-25 Mon	37	—	unknown	19:40–21:05 (good, 1.42 h)	79.2° 15:35	9.81	29%	120.5°
2041-02-26 Tue	34	—	unknown	19:45–21:05 (good, 1.33 h)	79.2° 15:30	9.77	20%	107.2°
2041-02-27 Wed	32	—	unknown	19:45–21:00 (good, 1.25 h)	79.2° 15:25	9.72	11%	93.5°
2041-02-28 Thu	31	—	unknown	19:45–20:55 (good, 1.17 h)	79.2° 15:20	9.68	5%	79.4°
2041-03-01 Fri	29	—	unknown	19:45–20:50 (good, 1.08 h)	79.2° 15:20	9.63	1%	65.3°
2041-03-02 Sat	26	—	unknown	19:50–20:45 (good, 0.92 h)	79.2° 15:15	9.58	0%	51.5°
2041-03-03 Sun	25	—	unknown	19:50–20:45 (good, 0.92 h)	79.2° 15:10	9.54	3%	38.5°
2041-03-04 Mon	22	—	unknown	19:50–20:40 (good, 0.83 h)	79.2° 15:05	9.49	8%	27.5°
2041-03-05 Tue	19	—	unknown	19:50–20:30 (good, 0.67 h)	79.2° 15:05	9.45	15%	21.0°
2041-03-06 Wed	15	—	unknown	19:50–20:20 (good, 0.5 h)	79.2° 15:00	9.4	23%	22.4°
2041-03-07 Thu	11	—	unknown	19:55–20:05 (good, 0.17 h)	79.2° 14:55	9.35	33%	30.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-02-06&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.