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: 03-17 (2), 03-18 (2), 03-19 (1), 03-20 (1), 03-21 (1) — by astronomy; check the weather when the night is within four days.

2035-03-17astronomy score per night — click a bar for that night2035-04-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-03-17 Sat	2	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.1° 14:15	8.88	62%	71.3°
2035-03-18 Sun	2	—	unknown	20:05–20:10 (marginal, 0.08 h)	79.1° 14:15	8.83	73%	84.1°
2035-03-19 Mon	1	—	unknown	20:05–20:10 (marginal, 0.08 h)	79.1° 14:10	8.78	82%	96.8°
2035-03-20 Tue	1	—	unknown	—	79.1° 14:05	8.73	90%	109.4°
2035-03-21 Wed	1	—	unknown	—	79.1° 14:00	8.68	96%	121.5°
2035-03-22 Thu	1	—	unknown	—	79.1° 14:00	8.63	99%	133.1°
2035-03-23 Fri	1	—	unknown	—	79.1° 13:55	8.58	100%	143.6°
2035-03-24 Sat	0	—	unknown	—	79.1° 13:50	8.52	99%	152.0°
2035-03-25 Sun	0	—	unknown	—	79.1° 14:45	8.47	96%	156.5°
2035-03-26 Mon	0	—	unknown	—	79.1° 14:40	8.42	91%	155.1°
2035-03-27 Tue	0	—	unknown	—	79.1° 14:40	8.36	85%	148.9°
2035-03-28 Wed	0	—	unknown	—	79.1° 14:35	8.31	77%	140.2°
2035-03-29 Thu	0	—	unknown	—	79.1° 14:30	8.26	69%	130.5°
2035-03-30 Fri	0	—	unknown	—	79.1° 14:25	8.2	60%	120.1°
2035-03-31 Sat	0	—	unknown	—	79.1° 14:20	8.15	50%	109.4°
2035-04-01 Sun	0	—	unknown	—	79.1° 14:20	8.09	41%	98.5°
2035-04-02 Mon	0	—	unknown	—	79.1° 14:15	8.04	31%	87.3°
2035-04-03 Tue	0	—	unknown	—	79.1° 14:10	7.98	22%	75.8°
2035-04-04 Wed	0	—	unknown	—	79.1° 14:05	7.93	14%	64.2°
2035-04-05 Thu	0	—	unknown	—	79.1° 14:05	7.87	8%	52.5°
2035-04-06 Fri	0	—	unknown	—	79.1° 14:00	7.82	3%	41.0°
2035-04-07 Sat	0	—	unknown	—	79.1° 13:55	7.76	0%	30.8°
2035-04-08 Sun	0	—	unknown	—	79.1° 13:50	7.7	0%	24.1°
2035-04-09 Mon	0	—	unknown	—	79.1° 13:45	7.65	3%	24.5°
2035-04-10 Tue	0	—	unknown	—	79.1° 13:45	7.59	8%	32.0°
2035-04-11 Wed	0	—	unknown	—	79.1° 13:40	7.53	16%	43.0°
2035-04-12 Thu	0	—	unknown	—	79.1° 13:35	7.48	26%	55.4°
2035-04-13 Fri	0	—	unknown	—	79.1° 13:30	7.42	37%	68.2°
2035-04-14 Sat	0	—	unknown	—	79.1° 13:25	7.36	48%	81.1°
2035-04-15 Sun	0	—	unknown	—	79.1° 13:25	7.3	59%	93.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-03-17&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.