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: 11-08 (2), 11-09 (2), 11-03 (1), 11-04 (1), 11-05 (1) — by astronomy; check the weather when the night is within four days.

2036-10-11astronomy score per night — click a bar for that night2036-11-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-10-11 Sat	0	—	unknown	—	50.2° 12:30	9.67	59%	87.7°
2036-10-12 Sun	0	—	unknown	—	50.2° 12:25	9.71	48%	73.8°
2036-10-13 Mon	0	—	unknown	—	50.2° 12:20	9.76	37%	59.7°
2036-10-14 Tue	0	—	unknown	—	50.2° 12:20	9.8	26%	45.4°
2036-10-15 Wed	0	—	unknown	—	50.2° 12:15	9.85	17%	30.9°
2036-10-16 Thu	0	—	unknown	—	50.2° 12:10	9.89	9%	16.4°
2036-10-17 Fri	0	—	unknown	—	50.2° 12:05	9.93	3%	2.0°
2036-10-18 Sat	0	—	unknown	—	50.2° 12:00	9.97	1%	12.6°
2036-10-19 Sun	0	—	unknown	—	50.2° 11:55	10.02	0%	26.7°
2036-10-20 Mon	0	—	unknown	—	50.2° 11:50	10.06	3%	40.6°
2036-10-21 Tue	0	—	unknown	—	50.2° 11:45	10.1	7%	54.1°
2036-10-22 Wed	0	—	unknown	—	50.2° 11:45	10.14	14%	67.3°
2036-10-23 Thu	0	—	unknown	—	50.2° 11:40	10.18	21%	80.0°
2036-10-24 Fri	0	—	unknown	—	50.2° 11:35	10.22	30%	92.4°
2036-10-25 Sat	0	—	unknown	—	50.2° 10:30	10.26	39%	104.6°
2036-10-26 Sun	0	—	unknown	—	50.2° 10:25	10.3	49%	116.6°
2036-10-27 Mon	0	—	unknown	—	50.2° 10:25	10.34	58%	128.4°
2036-10-28 Tue	0	—	unknown	—	50.2° 10:20	10.37	67%	140.3°
2036-10-29 Wed	0	—	unknown	—	50.2° 10:15	10.41	76%	152.2°
2036-10-30 Thu	0	—	unknown	—	50.2° 10:10	10.45	83%	164.2°
2036-10-31 Fri	0	—	unknown	—	50.2° 10:05	10.49	90%	176.4°
2036-11-01 Sat	0	—	unknown	—	50.2° 10:05	10.52	95%	171.0°
2036-11-02 Sun	0	—	unknown	—	50.2° 10:00	10.56	98%	158.3°
2036-11-03 Mon	1	—	unknown	—	50.2° 09:55	10.59	100%	145.3°
2036-11-04 Tue	1	—	unknown	—	50.2° 09:50	10.63	99%	132.0°
2036-11-05 Wed	1	—	unknown	—	50.2° 09:50	10.66	96%	118.5°
2036-11-06 Thu	1	—	unknown	—	50.2° 09:45	10.7	90%	104.8°
2036-11-07 Fri	1	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.2° 09:40	10.73	83%	90.9°
2036-11-08 Sat	2	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.2° 09:35	10.76	73%	76.9°
2036-11-09 Sun	2	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.2° 09:30	10.79	63%	62.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-10-11&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.