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: 11-03 (1), 11-04 (1), 11-05 (1), 11-06 (1), 11-07 (1) — by astronomy; check the weather when the night is within four days.

2028-10-09astronomy score per night — click a bar for that night2028-11-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-10-09 Mon	0	—	unknown	—	50.2° 12:40	9.58	66%	97.7°
2028-10-10 Tue	0	—	unknown	—	50.2° 12:35	9.62	56%	84.8°
2028-10-11 Wed	0	—	unknown	—	50.2° 12:30	9.67	45%	71.6°
2028-10-12 Thu	0	—	unknown	—	50.2° 12:25	9.71	34%	58.0°
2028-10-13 Fri	0	—	unknown	—	50.2° 12:20	9.76	24%	44.1°
2028-10-14 Sat	0	—	unknown	—	50.2° 12:20	9.8	15%	30.1°
2028-10-15 Sun	0	—	unknown	—	50.2° 12:15	9.84	7%	16.7°
2028-10-16 Mon	0	—	unknown	—	50.2° 12:10	9.89	2%	9.8°
2028-10-17 Tue	0	—	unknown	—	50.2° 12:05	9.93	0%	19.0°
2028-10-18 Wed	0	—	unknown	—	50.2° 12:00	9.97	1%	32.7°
2028-10-19 Thu	0	—	unknown	—	50.2° 11:55	10.01	5%	46.9°
2028-10-20 Fri	0	—	unknown	—	50.2° 11:50	10.06	11%	60.9°
2028-10-21 Sat	0	—	unknown	—	50.2° 11:45	10.1	19%	74.5°
2028-10-22 Sun	0	—	unknown	—	50.2° 11:40	10.14	28%	87.7°
2028-10-23 Mon	0	—	unknown	—	50.2° 11:40	10.18	37%	100.4°
2028-10-24 Tue	0	—	unknown	—	50.2° 11:35	10.22	47%	112.8°
2028-10-25 Wed	0	—	unknown	—	50.2° 11:30	10.26	57%	124.8°
2028-10-26 Thu	0	—	unknown	—	50.2° 11:25	10.3	66%	136.5°
2028-10-27 Fri	0	—	unknown	—	50.2° 11:25	10.33	75%	147.9°
2028-10-28 Sat	0	—	unknown	—	50.2° 10:20	10.37	82%	158.8°
2028-10-29 Sun	0	—	unknown	—	50.2° 10:15	10.41	89%	168.0°
2028-10-30 Mon	0	—	unknown	—	50.2° 10:10	10.45	94%	169.2°
2028-10-31 Tue	0	—	unknown	—	50.2° 10:05	10.48	98%	160.7°
2028-11-01 Wed	0	—	unknown	—	50.2° 10:05	10.52	100%	149.6°
2028-11-02 Thu	0	—	unknown	—	50.2° 10:00	10.56	100%	137.9°
2028-11-03 Fri	1	—	unknown	—	50.2° 09:55	10.59	98%	125.7°
2028-11-04 Sat	1	—	unknown	—	50.2° 09:50	10.63	94%	113.3°
2028-11-05 Sun	1	—	unknown	—	50.2° 09:45	10.66	88%	100.7°
2028-11-06 Mon	1	—	unknown	—	50.2° 09:45	10.69	80%	87.8°
2028-11-07 Tue	1	—	unknown	—	50.2° 09:40	10.73	71%	74.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-10-09&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.