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: 01-31 (93), 02-01 (91), 02-02 (88), 02-03 (86), 02-04 (82) — by astronomy; check the weather when the night is within four days.

2030-01-31astronomy score per night — click a bar for that night2030-03-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-01-31 Thu	93	—	unknown	19:15–22:45 (good, 3.5 h)	79.1° 17:15	10.79	4%	101.8°
2030-02-01 Fri	91	—	unknown	19:15–22:40 (good, 3.42 h)	79.1° 17:10	10.76	1%	88.4°
2030-02-02 Sat	88	—	unknown	19:15–22:35 (good, 3.33 h)	79.1° 17:05	10.72	0%	75.2°
2030-02-03 Sun	86	—	unknown	19:15–22:35 (good, 3.33 h)	79.1° 17:00	10.69	2%	62.4°
2030-02-04 Mon	82	—	unknown	19:20–22:30 (good, 3.17 h)	79.1° 16:55	10.65	6%	50.1°
2030-02-05 Tue	75	—	unknown	19:20–22:25 (good, 3.08 h)	79.1° 16:55	10.62	12%	38.3°
2030-02-06 Wed	65	—	unknown	19:20–22:20 (good, 3.0 h)	79.1° 16:50	10.58	19%	27.5°
2030-02-07 Thu	54	—	unknown	19:20–22:05 (good, 2.75 h)	79.1° 16:45	10.55	27%	18.8°
2030-02-08 Fri	44	—	unknown	19:20–21:55 (good, 2.58 h)	79.1° 16:40	10.51	36%	15.4°
2030-02-09 Sat	33	—	unknown	19:25–20:50 (good, 1.42 h)	79.1° 16:40	10.48	45%	20.0°
2030-02-10 Sun	25	—	unknown	19:25–22:25 (marginal, 3.0 h)	79.1° 16:35	10.44	54%	28.9°
2030-02-11 Mon	20	—	unknown	19:25–22:15 (marginal, 2.83 h)	79.1° 16:30	10.4	64%	39.3°
2030-02-12 Tue	19	—	unknown	19:25–22:05 (marginal, 2.67 h)	79.1° 16:25	10.36	72%	50.5°
2030-02-13 Wed	19	—	unknown	19:30–22:05 (marginal, 2.58 h)	79.1° 16:20	10.32	81%	62.1°
2030-02-14 Thu	22	—	unknown	19:30–22:05 (marginal, 2.58 h)	79.1° 16:20	10.28	88%	74.1°
2030-02-15 Fri	26	—	unknown	19:30–20:00 (good, 0.5 h)	79.1° 16:15	10.24	94%	86.4°
2030-02-16 Sat	32	—	unknown	19:30–21:00 (good, 1.5 h)	79.1° 16:10	10.2	98%	99.2°
2030-02-17 Sun	38	—	unknown	19:30–21:20 (good, 1.83 h)	79.1° 16:05	10.16	100%	112.2°
2030-02-18 Mon	41	—	unknown	19:35–21:25 (good, 1.83 h)	79.1° 16:00	10.12	99%	125.3°
2030-02-19 Tue	46	—	unknown	19:35–21:20 (good, 1.75 h)	79.1° 16:00	10.08	96%	138.4°
2030-02-20 Wed	45	—	unknown	19:35–21:20 (good, 1.75 h)	79.1° 15:55	10.04	91%	151.0°
2030-02-21 Thu	45	—	unknown	19:35–21:25 (good, 1.83 h)	79.1° 15:50	10.0	83%	161.3°
2030-02-22 Fri	42	—	unknown	19:40–21:20 (good, 1.67 h)	79.1° 15:45	9.95	74%	164.1°
2030-02-23 Sat	41	—	unknown	19:40–21:15 (good, 1.58 h)	79.1° 15:45	9.91	63%	156.4°
2030-02-24 Sun	38	—	unknown	19:40–21:10 (good, 1.5 h)	79.1° 15:40	9.87	52%	144.6°
2030-02-25 Mon	37	—	unknown	19:40–21:05 (good, 1.42 h)	79.1° 15:35	9.82	40%	131.8°
2030-02-26 Tue	34	—	unknown	19:45–21:05 (good, 1.33 h)	79.1° 15:30	9.78	30%	118.6°
2030-02-27 Wed	33	—	unknown	19:45–21:00 (good, 1.25 h)	79.1° 15:25	9.74	20%	105.5°
2030-02-28 Thu	31	—	unknown	19:45–20:55 (good, 1.17 h)	79.1° 15:25	9.69	12%	92.4°
2030-03-01 Fri	29	—	unknown	19:45–20:50 (good, 1.08 h)	79.1° 15:20	9.65	6%	79.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-01-31&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.