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: 01-28 (100), 01-29 (93), 01-30 (85), 01-31 (72), 02-12 (63) — by astronomy; check the weather when the night is within four days.

2028-01-28astronomy score per night — click a bar for that night2028-02-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-01-28 Fri	100	—	unknown	19:10–23:00 (good, 3.83 h)	79.1° 17:25	10.9	5%	60.7°
2028-01-29 Sat	93	—	unknown	19:10–22:55 (good, 3.75 h)	79.1° 17:25	10.87	10%	49.4°
2028-01-30 Sun	85	—	unknown	19:10–22:50 (good, 3.67 h)	79.1° 17:20	10.84	16%	38.3°
2028-01-31 Mon	72	—	unknown	19:15–22:45 (good, 3.5 h)	79.1° 17:15	10.81	23%	27.7°
2028-02-01 Tue	59	—	unknown	19:15–22:30 (good, 3.25 h)	79.1° 17:10	10.77	32%	18.4°
2028-02-02 Wed	47	—	unknown	19:15–22:15 (good, 3.0 h)	79.1° 17:05	10.74	41%	14.1°
2028-02-03 Thu	34	—	unknown	19:15–19:45 (good, 0.5 h)	79.1° 17:05	10.71	51%	19.1°
2028-02-04 Fri	24	—	unknown	19:15–22:45 (marginal, 3.5 h)	79.1° 17:00	10.67	62%	29.3°
2028-02-05 Sat	20	—	unknown	19:20–22:35 (marginal, 3.25 h)	79.1° 16:55	10.64	72%	41.5°
2028-02-06 Sun	21	—	unknown	19:20–22:25 (marginal, 3.08 h)	79.1° 16:50	10.6	81%	54.7°
2028-02-07 Mon	25	—	unknown	19:20–22:25 (marginal, 3.08 h)	79.1° 16:45	10.57	90%	68.5°
2028-02-08 Tue	32	—	unknown	19:20–20:00 (good, 0.67 h)	79.1° 16:45	10.53	96%	82.9°
2028-02-09 Wed	41	—	unknown	19:25–21:20 (good, 1.92 h)	79.1° 16:40	10.49	99%	97.6°
2028-02-10 Thu	51	—	unknown	19:25–21:50 (good, 2.42 h)	79.1° 16:35	10.46	100%	112.3°
2028-02-11 Fri	57	—	unknown	19:25–21:55 (good, 2.5 h)	79.1° 16:30	10.42	97%	127.0°
2028-02-12 Sat	63	—	unknown	19:25–21:50 (good, 2.42 h)	79.1° 16:30	10.38	92%	141.1°
2028-02-13 Sun	63	—	unknown	19:25–21:55 (good, 2.5 h)	79.1° 16:25	10.34	84%	154.2°
2028-02-14 Mon	60	—	unknown	19:30–21:50 (good, 2.33 h)	79.1° 16:20	10.3	75%	164.0°
2028-02-15 Tue	58	—	unknown	19:30–21:50 (good, 2.33 h)	79.1° 16:15	10.27	65%	164.6°
2028-02-16 Wed	56	—	unknown	19:30–21:45 (good, 2.25 h)	79.1° 16:10	10.23	54%	156.0°
2028-02-17 Thu	55	—	unknown	19:30–21:40 (good, 2.17 h)	79.1° 16:10	10.18	44%	144.8°
2028-02-18 Fri	51	—	unknown	19:35–21:35 (good, 2.0 h)	79.1° 16:05	10.14	34%	133.1°
2028-02-19 Sat	49	—	unknown	19:35–21:30 (good, 1.92 h)	79.1° 16:00	10.1	25%	121.3°
2028-02-20 Sun	47	—	unknown	19:35–21:30 (good, 1.92 h)	79.1° 15:55	10.06	17%	109.6°
2028-02-21 Mon	46	—	unknown	19:35–21:25 (good, 1.83 h)	79.1° 15:50	10.02	10%	98.0°
2028-02-22 Tue	44	—	unknown	19:35–21:20 (good, 1.75 h)	79.1° 15:50	9.98	6%	86.5°
2028-02-23 Wed	41	—	unknown	19:40–21:15 (good, 1.58 h)	79.1° 15:45	9.93	2%	75.0°
2028-02-24 Thu	39	—	unknown	19:40–21:15 (good, 1.58 h)	79.1° 15:40	9.89	0%	63.6°
2028-02-25 Fri	38	—	unknown	19:40–21:10 (good, 1.5 h)	79.1° 15:35	9.85	0%	52.3°
2028-02-26 Sat	36	—	unknown	19:40–21:05 (good, 1.42 h)	79.1° 15:35	9.8	2%	41.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-01-28&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.