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: 03-13 (8), 03-14 (6), 03-15 (4), 03-16 (3), 03-17 (2) — by astronomy; check the weather when the night is within four days.

2043-03-13astronomy score per night — click a bar for that night2043-04-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-03-13 Fri	8	—	unknown	19:25–20:35 (marginal, 1.17 h)	79.2° 14:35	9.08	9%	18.2°
2043-03-14 Sat	6	—	unknown	20:00–20:30 (marginal, 0.5 h)	79.2° 14:30	9.03	17%	19.0°
2043-03-15 Sun	4	—	unknown	20:05–20:25 (marginal, 0.33 h)	79.2° 14:25	8.98	27%	28.2°
2043-03-16 Mon	3	—	unknown	20:05–20:25 (marginal, 0.33 h)	79.2° 14:20	8.93	38%	40.3°
2043-03-17 Tue	2	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:15	8.88	49%	53.1°
2043-03-18 Wed	1	—	unknown	20:05–20:10 (marginal, 0.08 h)	79.2° 14:15	8.83	60%	66.0°
2043-03-19 Thu	1	—	unknown	—	79.2° 14:10	8.78	70%	78.7°
2043-03-20 Fri	1	—	unknown	—	79.2° 14:05	8.73	79%	91.3°
2043-03-21 Sat	1	—	unknown	—	79.2° 14:00	8.68	87%	103.6°
2043-03-22 Sun	1	—	unknown	—	79.2° 14:00	8.62	93%	115.7°
2043-03-23 Mon	1	—	unknown	—	79.2° 13:55	8.57	97%	127.4°
2043-03-24 Tue	0	—	unknown	—	79.2° 13:50	8.52	100%	138.7°
2043-03-25 Wed	0	—	unknown	—	79.2° 13:45	8.47	100%	149.3°
2043-03-26 Thu	0	—	unknown	—	79.2° 13:40	8.41	98%	158.1°
2043-03-27 Fri	0	—	unknown	—	79.2° 13:40	8.36	95%	162.8°
2043-03-28 Sat	0	—	unknown	—	79.2° 13:35	8.31	90%	160.3°
2043-03-29 Sun	0	—	unknown	—	79.2° 14:30	8.25	84%	152.6°
2043-03-30 Mon	0	—	unknown	—	79.2° 14:25	8.2	76%	142.8°
2043-03-31 Tue	0	—	unknown	—	79.2° 14:20	8.14	68%	132.0°
2043-04-01 Wed	0	—	unknown	—	79.2° 14:20	8.09	58%	120.8°
2043-04-02 Thu	0	—	unknown	—	79.2° 14:15	8.03	49%	109.2°
2043-04-03 Fri	0	—	unknown	—	79.2° 14:10	7.98	38%	97.2°
2043-04-04 Sat	0	—	unknown	—	79.2° 14:05	7.92	29%	84.7°
2043-04-05 Sun	0	—	unknown	—	79.2° 14:05	7.87	19%	71.9°
2043-04-06 Mon	0	—	unknown	—	79.2° 14:00	7.81	11%	58.7°
2043-04-07 Tue	0	—	unknown	—	79.2° 13:55	7.76	5%	45.4°
2043-04-08 Wed	0	—	unknown	—	79.2° 13:50	7.7	1%	32.4°
2043-04-09 Thu	0	—	unknown	—	79.2° 13:45	7.64	0%	21.3°
2043-04-10 Fri	0	—	unknown	—	79.2° 13:45	7.59	2%	17.2°
2043-04-11 Sat	0	—	unknown	—	79.2° 13:40	7.53	7%	24.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-03-13&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.