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: 11-26 (28), 11-25 (27), 11-24 (26), 11-28 (26), 11-23 (25) — by astronomy; check the weather when the night is within four days.

2031-11-05astronomy score per night — click a bar for that night2031-12-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-11-05 Wed	1	—	unknown	—	50.2° 09:50	10.64	63%	68.1°
2031-11-06 Thu	1	—	unknown	—	50.2° 09:45	10.67	54%	56.5°
2031-11-07 Fri	1	—	unknown	—	50.2° 09:45	10.7	44%	44.8°
2031-11-08 Sat	2	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.2° 09:40	10.74	35%	33.1°
2031-11-09 Sun	2	—	unknown	05:20–05:30 (marginal, 0.17 h)	50.2° 09:35	10.77	26%	21.5°
2031-11-10 Mon	4	—	unknown	05:15–05:30 (marginal, 0.25 h)	50.2° 09:30	10.8	17%	11.1°
2031-11-11 Tue	5	—	unknown	05:10–05:35 (marginal, 0.42 h)	50.2° 09:25	10.83	10%	10.1°
2031-11-12 Wed	6	—	unknown	05:10–05:35 (marginal, 0.42 h)	50.2° 09:25	10.86	5%	20.6°
2031-11-13 Thu	8	—	unknown	05:30–05:35 (good, 0.08 h)	50.2° 09:20	10.89	1%	33.5°
2031-11-14 Fri	9	—	unknown	05:30–05:35 (good, 0.08 h)	50.2° 09:15	10.92	0%	47.1°
2031-11-15 Sat	11	—	unknown	05:25–05:35 (good, 0.17 h)	50.2° 09:10	10.95	1%	61.2°
2031-11-16 Sun	13	—	unknown	05:20–05:40 (good, 0.33 h)	50.2° 09:05	10.98	6%	75.4°
2031-11-17 Mon	14	—	unknown	05:15–05:40 (good, 0.42 h)	50.2° 09:05	11.01	12%	89.8°
2031-11-18 Tue	16	—	unknown	05:10–05:40 (good, 0.5 h)	50.2° 09:00	11.04	21%	104.2°
2031-11-19 Wed	18	—	unknown	05:10–05:40 (good, 0.5 h)	50.2° 08:55	11.06	31%	118.4°
2031-11-20 Thu	20	—	unknown	05:05–05:40 (good, 0.58 h)	50.2° 08:50	11.09	42%	132.4°
2031-11-21 Fri	22	—	unknown	05:00–05:45 (good, 0.75 h)	50.2° 08:50	11.11	54%	146.1°
2031-11-22 Sat	23	—	unknown	04:55–05:45 (good, 0.83 h)	50.2° 08:45	11.14	64%	159.2°
2031-11-23 Sun	25	—	unknown	04:55–05:45 (good, 0.83 h)	50.2° 08:40	11.16	75%	170.0°
2031-11-24 Mon	26	—	unknown	04:50–05:45 (good, 0.92 h)	50.2° 08:35	11.19	83%	168.5°
2031-11-25 Tue	27	—	unknown	04:45–05:45 (good, 1.0 h)	50.2° 08:30	11.21	90%	157.3°
2031-11-26 Wed	28	—	unknown	04:50–05:50 (good, 1.0 h)	50.2° 08:30	11.23	96%	144.9°
2031-11-27 Thu	25	—	unknown	04:45–05:50 (good, 1.08 h)	50.2° 08:25	11.25	99%	132.4°
2031-11-28 Fri	26	—	unknown	04:45–05:50 (good, 1.08 h)	50.2° 08:20	11.27	100%	120.0°
2031-11-29 Sat	23	—	unknown	04:50–05:50 (good, 1.0 h)	50.2° 08:15	11.29	99%	107.7°
2031-11-30 Sun	20	—	unknown	05:15–05:50 (good, 0.58 h)	50.2° 08:10	11.31	96%	95.6°
2031-12-01 Mon	17	—	unknown	04:05–05:55 (marginal, 1.83 h)	50.2° 08:10	11.33	92%	83.7°
2031-12-02 Tue	15	—	unknown	04:05–05:55 (marginal, 1.83 h)	50.2° 08:05	11.34	86%	71.9°
2031-12-03 Wed	14	—	unknown	04:05–05:55 (marginal, 1.83 h)	50.2° 08:00	11.36	79%	60.2°
2031-12-04 Thu	14	—	unknown	04:00–05:55 (marginal, 1.92 h)	50.2° 07:55	11.38	70%	48.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-11-05&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.