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: 03-14 (6), 03-15 (5), 03-16 (4), 03-17 (3), 03-18 (3) — by astronomy; check the weather when the night is within four days.

2028-03-14astronomy score per night — click a bar for that night2028-04-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-03-14 Tue	6	—	unknown	19:30–20:25 (marginal, 0.92 h)	79.1° 14:25	9.0	80%	159.6°
2028-03-15 Wed	5	—	unknown	20:05–20:25 (marginal, 0.33 h)	79.1° 14:20	8.95	70%	148.5°
2028-03-16 Thu	4	—	unknown	20:05–20:20 (marginal, 0.25 h)	79.1° 14:20	8.9	60%	136.6°
2028-03-17 Fri	3	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.1° 14:15	8.85	50%	124.6°
2028-03-18 Sat	3	—	unknown	20:05–20:10 (marginal, 0.08 h)	79.1° 14:10	8.8	41%	112.7°
2028-03-19 Sun	1	—	unknown	19:35–19:40 (marginal, 0.08 h)	79.1° 14:05	8.75	31%	101.0°
2028-03-20 Mon	1	—	unknown	—	79.1° 14:00	8.7	23%	89.5°
2028-03-21 Tue	1	—	unknown	—	79.1° 14:00	8.64	16%	78.0°
2028-03-22 Wed	1	—	unknown	—	79.1° 13:55	8.59	9%	66.6°
2028-03-23 Thu	1	—	unknown	—	79.1° 13:50	8.54	5%	55.3°
2028-03-24 Fri	0	—	unknown	—	79.1° 13:45	8.49	2%	44.0°
2028-03-25 Sat	0	—	unknown	—	79.1° 13:45	8.43	0%	33.0°
2028-03-26 Sun	0	—	unknown	—	79.1° 14:40	8.38	1%	22.9°
2028-03-27 Mon	0	—	unknown	—	79.1° 14:35	8.33	3%	15.4°
2028-03-28 Tue	0	—	unknown	—	79.1° 14:30	8.27	7%	15.8°
2028-03-29 Wed	0	—	unknown	—	79.1° 14:25	8.22	13%	23.9°
2028-03-30 Thu	0	—	unknown	—	79.1° 14:25	8.16	21%	34.9°
2028-03-31 Fri	0	—	unknown	—	79.1° 14:20	8.11	30%	46.9°
2028-04-01 Sat	0	—	unknown	—	79.1° 14:15	8.05	40%	59.6°
2028-04-02 Sun	0	—	unknown	—	79.1° 14:10	8.0	51%	72.7°
2028-04-03 Mon	0	—	unknown	—	79.1° 14:05	7.94	63%	86.2°
2028-04-04 Tue	0	—	unknown	—	79.1° 14:05	7.89	73%	100.1°
2028-04-05 Wed	0	—	unknown	—	79.1° 14:00	7.83	83%	114.2°
2028-04-06 Thu	0	—	unknown	—	79.1° 13:55	7.78	91%	128.3°
2028-04-07 Fri	0	—	unknown	—	79.1° 13:50	7.72	97%	142.3°
2028-04-08 Sat	0	—	unknown	—	79.1° 13:50	7.66	100%	155.2°
2028-04-09 Sun	0	—	unknown	—	79.1° 13:45	7.61	100%	164.6°
2028-04-10 Mon	0	—	unknown	—	79.1° 13:40	7.55	97%	163.2°
2028-04-11 Tue	0	—	unknown	—	79.1° 13:35	7.49	92%	153.3°
2028-04-12 Wed	0	—	unknown	—	79.1° 13:30	7.44	85%	141.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-03-14&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.