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 3C 273: 11-10 (4), 11-08 (3), 11-09 (3), 11-03 (1), 11-04 (1) — by astronomy; check the weather when the night is within four days.

2035-10-12astronomy score per night — click a bar for that night2035-11-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-10-12 Fri	0	—	unknown	—	50.2° 12:30	9.68	81%	142.1°
2035-10-13 Sat	0	—	unknown	—	50.2° 12:25	9.73	89%	154.8°
2035-10-14 Sun	0	—	unknown	—	50.2° 12:20	9.77	94%	167.7°
2035-10-15 Mon	0	—	unknown	—	50.2° 12:15	9.81	98%	177.6°
2035-10-16 Tue	0	—	unknown	—	50.2° 12:15	9.86	100%	164.9°
2035-10-17 Wed	0	—	unknown	—	50.2° 12:10	9.9	99%	151.0°
2035-10-18 Thu	0	—	unknown	—	50.2° 12:05	9.94	96%	136.8°
2035-10-19 Fri	0	—	unknown	—	50.2° 12:00	9.98	90%	122.5°
2035-10-20 Sat	0	—	unknown	—	50.2° 11:55	10.03	82%	108.1°
2035-10-21 Sun	0	—	unknown	—	50.2° 11:50	10.07	72%	93.7°
2035-10-22 Mon	0	—	unknown	—	50.2° 11:45	10.11	61%	79.4°
2035-10-23 Tue	0	—	unknown	—	50.2° 11:40	10.15	50%	65.3°
2035-10-24 Wed	0	—	unknown	—	50.2° 11:40	10.19	38%	51.3°
2035-10-25 Thu	0	—	unknown	—	50.2° 11:35	10.23	28%	37.5°
2035-10-26 Fri	0	—	unknown	—	50.2° 11:30	10.27	19%	23.9°
2035-10-27 Sat	0	—	unknown	—	50.2° 10:25	10.31	11%	10.5°
2035-10-28 Sun	0	—	unknown	—	50.2° 10:20	10.35	5%	3.6°
2035-10-29 Mon	0	—	unknown	—	50.2° 10:20	10.38	2%	16.1°
2035-10-30 Tue	0	—	unknown	—	50.2° 10:15	10.42	0%	28.9°
2035-10-31 Wed	0	—	unknown	—	50.2° 10:10	10.46	1%	41.5°
2035-11-01 Thu	0	—	unknown	—	50.2° 10:05	10.49	3%	53.9°
2035-11-02 Fri	0	—	unknown	—	50.2° 10:00	10.53	8%	66.1°
2035-11-03 Sat	1	—	unknown	—	50.2° 10:00	10.57	14%	78.1°
2035-11-04 Sun	1	—	unknown	—	50.2° 09:55	10.6	21%	90.0°
2035-11-05 Mon	1	—	unknown	—	50.2° 09:50	10.64	29%	101.8°
2035-11-06 Tue	1	—	unknown	—	50.2° 09:45	10.67	38%	113.6°
2035-11-07 Wed	1	—	unknown	05:55–06:00 (marginal, 0.08 h)	50.2° 09:45	10.7	47%	125.5°
2035-11-08 Thu	3	—	unknown	05:50–06:00 (marginal, 0.17 h)	50.2° 09:40	10.74	56%	137.6°
2035-11-09 Fri	3	—	unknown	05:50–06:05 (marginal, 0.25 h)	50.2° 09:35	10.77	66%	149.9°
2035-11-10 Sat	4	—	unknown	05:15–05:30 (marginal, 0.25 h)	50.2° 09:30	10.8	75%	162.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-10-12&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.