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: 01-03 (100), 01-04 (100), 01-05 (100), 01-06 (100), 01-07 (100) — by astronomy; check the weather when the night is within four days.

2037-01-01astronomy score per night — click a bar for that night2037-01-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-01-01 Thu	55	—	unknown	18:45–19:45 (good, 1.0 h)	79.2° 19:10	11.45	100%	68.6°
2037-01-02 Fri	75	—	unknown	18:45–22:10 (good, 3.42 h)	79.2° 19:05	11.44	99%	81.9°
2037-01-03 Sat	100	—	unknown	18:45–23:40 (good, 4.92 h)	79.1° 19:00	11.42	95%	95.5°
2037-01-04 Sun	100	—	unknown	18:45–00:10 (good, 5.42 h)	79.2° 19:00	11.41	89%	108.9°
2037-01-05 Mon	100	—	unknown	18:45–00:20 (good, 5.58 h)	79.2° 18:55	11.4	80%	122.0°
2037-01-06 Tue	100	—	unknown	18:50–00:15 (good, 5.42 h)	79.2° 18:50	11.38	70%	134.2°
2037-01-07 Wed	100	—	unknown	18:50–00:15 (good, 5.42 h)	79.2° 18:45	11.37	59%	145.0°
2037-01-08 Thu	100	—	unknown	18:50–00:15 (good, 5.42 h)	79.1° 18:45	11.35	48%	152.8°
2037-01-09 Fri	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:40	11.34	37%	155.3°
2037-01-10 Sat	100	—	unknown	18:50–00:05 (good, 5.25 h)	79.2° 18:35	11.32	27%	151.5°
2037-01-11 Sun	100	—	unknown	18:55–00:05 (good, 5.17 h)	79.2° 18:30	11.3	19%	143.5°
2037-01-12 Mon	100	—	unknown	18:55–00:00 (good, 5.08 h)	79.1° 18:25	11.28	11%	133.6°
2037-01-13 Tue	100	—	unknown	18:55–23:55 (good, 5.0 h)	79.1° 18:25	11.26	6%	123.0°
2037-01-14 Wed	100	—	unknown	18:55–23:50 (good, 4.92 h)	79.2° 18:20	11.24	2%	112.0°
2037-01-15 Thu	100	—	unknown	18:55–23:50 (good, 4.92 h)	79.2° 18:15	11.22	0%	101.0°
2037-01-16 Fri	100	—	unknown	18:55–23:45 (good, 4.83 h)	79.2° 18:10	11.2	0%	90.0°
2037-01-17 Sat	100	—	unknown	19:00–23:40 (good, 4.67 h)	79.1° 18:05	11.17	2%	79.1°
2037-01-18 Sun	100	—	unknown	19:00–23:35 (good, 4.58 h)	79.2° 18:05	11.15	6%	68.4°
2037-01-19 Mon	100	—	unknown	19:00–23:30 (good, 4.5 h)	79.2° 18:00	11.12	11%	58.0°
2037-01-20 Tue	93	—	unknown	19:00–23:30 (good, 4.5 h)	79.2° 17:55	11.1	17%	47.9°
2037-01-21 Wed	87	—	unknown	19:05–23:25 (good, 4.33 h)	79.2° 17:50	11.07	25%	38.6°
2037-01-22 Thu	74	—	unknown	19:05–23:05 (good, 4.0 h)	79.1° 17:50	11.05	34%	30.6°
2037-01-23 Fri	58	—	unknown	19:05–22:55 (good, 3.83 h)	79.2° 17:45	11.02	43%	25.4°
2037-01-24 Sat	43	—	unknown	19:05–20:50 (good, 1.75 h)	79.2° 17:40	10.99	53%	25.3°
2037-01-25 Sun	31	—	unknown	19:05–23:25 (marginal, 4.33 h)	79.2° 17:35	10.96	63%	30.6°
2037-01-26 Mon	26	—	unknown	19:10–23:10 (marginal, 4.0 h)	79.1° 17:30	10.93	73%	39.5°
2037-01-27 Tue	25	—	unknown	19:10–23:00 (marginal, 3.83 h)	79.1° 17:30	10.9	82%	50.4°
2037-01-28 Wed	28	—	unknown	19:10–23:00 (marginal, 3.83 h)	79.2° 17:25	10.87	90%	62.7°
2037-01-29 Thu	36	—	unknown	19:10–19:50 (good, 0.67 h)	79.2° 17:20	10.84	96%	75.7°
2037-01-30 Fri	47	—	unknown	19:10–21:05 (good, 1.92 h)	79.2° 17:15	10.81	99%	89.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-01-01&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.