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: 11-13 (8), 11-12 (7), 11-11 (6), 11-10 (5), 11-09 (4) — by astronomy; check the weather when the night is within four days.

2034-10-15astronomy score per night — click a bar for that night2034-11-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-10-15 Sun	0	—	unknown	—	50.2° 12:15	9.82	12%	56.1°
2034-10-16 Mon	0	—	unknown	—	50.2° 12:10	9.87	18%	67.8°
2034-10-17 Tue	0	—	unknown	—	50.2° 12:10	9.91	26%	79.6°
2034-10-18 Wed	0	—	unknown	—	50.2° 12:00	9.95	35%	91.6°
2034-10-19 Thu	0	—	unknown	—	50.2° 12:00	9.99	44%	103.6°
2034-10-20 Fri	0	—	unknown	—	50.2° 11:50	10.04	54%	116.0°
2034-10-21 Sat	0	—	unknown	—	50.2° 11:50	10.08	64%	128.6°
2034-10-22 Sun	0	—	unknown	—	50.2° 11:45	10.12	74%	141.7°
2034-10-23 Mon	0	—	unknown	—	50.2° 11:40	10.16	83%	155.1°
2034-10-24 Tue	0	—	unknown	—	50.2° 11:35	10.2	90%	168.8°
2034-10-25 Wed	0	—	unknown	—	50.2° 11:35	10.24	96%	174.6°
2034-10-26 Thu	0	—	unknown	—	50.2° 11:30	10.28	99%	160.8°
2034-10-27 Fri	0	—	unknown	—	50.2° 11:25	10.32	100%	145.9°
2034-10-28 Sat	0	—	unknown	—	50.2° 10:20	10.35	97%	130.8°
2034-10-29 Sun	0	—	unknown	—	50.2° 10:15	10.39	91%	115.8°
2034-10-30 Mon	0	—	unknown	—	50.2° 10:15	10.43	84%	100.9°
2034-10-31 Tue	0	—	unknown	—	50.2° 10:10	10.47	74%	86.4°
2034-11-01 Wed	0	—	unknown	—	50.2° 10:05	10.5	63%	72.3°
2034-11-02 Thu	0	—	unknown	—	50.2° 10:00	10.54	52%	58.6°
2034-11-03 Fri	0	—	unknown	—	50.2° 09:55	10.58	42%	45.4°
2034-11-04 Sat	1	—	unknown	—	50.2° 09:55	10.61	32%	32.5°
2034-11-05 Sun	1	—	unknown	—	50.2° 09:50	10.64	23%	20.0°
2034-11-06 Mon	1	—	unknown	—	50.2° 09:45	10.68	15%	8.1°
2034-11-07 Tue	2	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.2° 09:40	10.71	9%	6.2°
2034-11-08 Wed	3	—	unknown	05:50–06:05 (marginal, 0.25 h)	50.2° 09:40	10.75	4%	17.5°
2034-11-09 Thu	4	—	unknown	05:45–06:05 (marginal, 0.33 h)	50.2° 09:35	10.78	1%	29.3°
2034-11-10 Fri	5	—	unknown	05:15–05:30 (marginal, 0.25 h)	50.2° 09:30	10.81	0%	41.1°
2034-11-11 Sat	6	—	unknown	05:10–05:35 (marginal, 0.42 h)	50.2° 09:25	10.84	1%	52.9°
2034-11-12 Sun	7	—	unknown	05:05–06:05 (marginal, 1.0 h)	50.2° 09:20	10.87	3%	64.7°
2034-11-13 Mon	8	—	unknown	05:30–05:35 (good, 0.08 h)	50.2° 09:20	10.9	7%	76.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-10-15&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.