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: 03-19 (2), 03-20 (1), 03-21 (1), 03-22 (1) — by astronomy; check the weather when the night is within four days.

2045-03-19astronomy score per night — click a bar for that night2045-04-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-03-19 Sun	2	—	unknown	19:35–19:40 (marginal, 0.08 h)	79.2° 14:10	8.75	2%	24.7°
2045-03-20 Mon	1	—	unknown	—	79.2° 14:05	8.7	5%	16.4°
2045-03-21 Tue	1	—	unknown	—	79.2° 14:00	8.65	11%	15.9°
2045-03-22 Wed	1	—	unknown	—	79.2° 13:55	8.6	18%	24.0°
2045-03-23 Thu	0	—	unknown	—	79.2° 13:50	8.54	27%	35.5°
2045-03-24 Fri	0	—	unknown	—	79.2° 13:50	8.49	38%	48.1°
2045-03-25 Sat	0	—	unknown	—	79.2° 13:45	8.44	49%	61.3°
2045-03-26 Sun	0	—	unknown	—	79.2° 14:40	8.39	60%	74.8°
2045-03-27 Mon	0	—	unknown	—	79.2° 14:35	8.33	71%	88.6°
2045-03-28 Tue	0	—	unknown	—	79.2° 14:30	8.28	81%	102.6°
2045-03-29 Wed	0	—	unknown	—	79.2° 14:30	8.22	89%	116.6°
2045-03-30 Thu	0	—	unknown	—	79.2° 14:25	8.17	95%	130.4°
2045-03-31 Fri	0	—	unknown	—	79.2° 14:20	8.12	99%	143.8°
2045-04-01 Sat	0	—	unknown	—	79.2° 14:15	8.06	100%	155.9°
2045-04-02 Sun	0	—	unknown	—	79.2° 14:15	8.01	98%	164.3°
2045-04-03 Mon	0	—	unknown	—	79.2° 14:10	7.95	94%	163.1°
2045-04-04 Tue	0	—	unknown	—	79.2° 14:05	7.89	88%	154.1°
2045-04-05 Wed	0	—	unknown	—	79.2° 14:00	7.84	81%	142.9°
2045-04-06 Thu	0	—	unknown	—	79.2° 13:55	7.78	72%	131.4°
2045-04-07 Fri	0	—	unknown	—	79.2° 13:55	7.73	63%	119.8°
2045-04-08 Sat	0	—	unknown	—	79.2° 13:50	7.67	54%	108.3°
2045-04-09 Sun	0	—	unknown	—	79.2° 13:45	7.61	44%	96.8°
2045-04-10 Mon	0	—	unknown	—	79.2° 13:40	7.56	35%	85.4°
2045-04-11 Tue	0	—	unknown	—	79.2° 13:35	7.5	26%	73.9°
2045-04-12 Wed	0	—	unknown	—	79.2° 13:35	7.44	18%	62.4°
2045-04-13 Thu	0	—	unknown	—	79.2° 13:30	7.39	12%	50.8°
2045-04-14 Fri	0	—	unknown	—	79.2° 13:25	7.33	6%	39.2°
2045-04-15 Sat	0	—	unknown	—	79.2° 13:20	7.27	2%	28.0°
2045-04-16 Sun	0	—	unknown	—	79.2° 13:20	7.21	0%	18.5°
2045-04-17 Mon	0	—	unknown	—	79.2° 13:15	7.15	1%	15.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-03-19&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.