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: 02-08 (76), 02-09 (72), 02-10 (70), 02-11 (68), 02-12 (66) — by astronomy; check the weather when the night is within four days.

2040-02-08astronomy score per night — click a bar for that night2040-03-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2040-02-08 Wed	76	—	unknown	19:20–22:15 (good, 2.92 h)	79.2° 16:45	10.53	18%	122.5°
2040-02-09 Thu	72	—	unknown	19:25–22:10 (good, 2.75 h)	79.2° 16:40	10.49	10%	109.1°
2040-02-10 Fri	70	—	unknown	19:25–22:10 (good, 2.75 h)	79.2° 16:35	10.45	4%	95.4°
2040-02-11 Sat	68	—	unknown	19:25–22:05 (good, 2.67 h)	79.2° 16:30	10.42	1%	81.7°
2040-02-12 Sun	66	—	unknown	19:25–22:00 (good, 2.58 h)	79.2° 16:30	10.38	0%	68.1°
2040-02-13 Mon	64	—	unknown	19:25–21:55 (good, 2.5 h)	79.2° 16:25	10.34	3%	55.1°
2040-02-14 Tue	58	—	unknown	19:30–21:55 (good, 2.42 h)	79.2° 16:20	10.3	7%	43.0°
2040-02-15 Wed	52	—	unknown	19:30–21:50 (good, 2.33 h)	79.2° 16:15	10.26	14%	32.4°
2040-02-16 Thu	43	—	unknown	19:30–21:35 (good, 2.08 h)	79.2° 16:10	10.22	22%	24.7°
2040-02-17 Fri	35	—	unknown	19:30–21:25 (good, 1.92 h)	79.2° 16:10	10.18	31%	22.4°
2040-02-18 Sat	27	—	unknown	19:35–20:55 (good, 1.33 h)	79.2° 16:05	10.14	41%	26.3°
2040-02-19 Sun	21	—	unknown	19:35–21:55 (marginal, 2.33 h)	79.2° 16:00	10.1	50%	34.1°
2040-02-20 Mon	17	—	unknown	19:35–21:45 (marginal, 2.17 h)	79.2° 15:55	10.06	60%	43.6°
2040-02-21 Tue	15	—	unknown	19:35–21:40 (marginal, 2.08 h)	79.2° 15:55	10.02	69%	53.8°
2040-02-22 Wed	15	—	unknown	19:35–21:35 (marginal, 2.0 h)	79.2° 15:50	9.97	77%	64.4°
2040-02-23 Thu	16	—	unknown	19:40–21:30 (marginal, 1.83 h)	79.2° 15:45	9.93	84%	75.2°
2040-02-24 Fri	17	—	unknown	19:40–21:35 (marginal, 1.92 h)	79.2° 15:40	9.89	91%	86.3°
2040-02-25 Sat	21	—	unknown	19:40–20:20 (good, 0.67 h)	79.2° 15:35	9.84	96%	97.5°
2040-02-26 Sun	24	—	unknown	19:40–20:45 (good, 1.08 h)	79.2° 15:35	9.8	99%	108.8°
2040-02-27 Mon	26	—	unknown	19:45–20:50 (good, 1.08 h)	79.2° 15:30	9.75	100%	120.2°
2040-02-28 Tue	26	—	unknown	19:45–20:45 (good, 1.0 h)	79.2° 15:25	9.71	99%	131.5°
2040-02-29 Wed	28	—	unknown	19:45–20:45 (good, 1.0 h)	79.2° 15:20	9.66	96%	142.3°
2040-03-01 Thu	29	—	unknown	19:45–20:50 (good, 1.08 h)	79.2° 15:15	9.62	91%	151.6°
2040-03-02 Fri	26	—	unknown	19:50–20:45 (good, 0.92 h)	79.2° 15:15	9.57	84%	157.4°
2040-03-03 Sat	25	—	unknown	19:50–20:40 (good, 0.83 h)	79.2° 15:10	9.53	75%	156.3°
2040-03-04 Sun	23	—	unknown	19:50–20:40 (good, 0.83 h)	79.2° 15:05	9.48	65%	148.9°
2040-03-05 Mon	22	—	unknown	19:50–20:35 (good, 0.75 h)	79.2° 15:00	9.43	54%	138.2°
2040-03-06 Tue	20	—	unknown	19:55–20:30 (good, 0.58 h)	79.2° 15:00	9.39	43%	126.1°
2040-03-07 Wed	18	—	unknown	19:55–20:25 (good, 0.5 h)	79.2° 14:55	9.34	32%	113.3°
2040-03-08 Thu	16	—	unknown	19:55–20:20 (good, 0.42 h)	79.2° 14:50	9.29	22%	100.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2040-02-08&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.