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 Vega: 11-17 (63), 11-18 (63), 11-19 (62), 11-16 (61), 11-20 (61) — by astronomy; check the weather when the night is within four days.

2027-11-13astronomy score per night — click a bar for that night2027-12-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2027-11-13 Sat	43	—	unknown	18:40–20:50 (good, 2.17 h)	87.1° 15:30	10.89	100%	100.5°
2027-11-14 Sun	47	—	unknown	18:40–21:00 (good, 2.33 h)	87.1° 15:25	10.92	99%	106.0°
2027-11-15 Mon	51	—	unknown	18:40–21:00 (good, 2.33 h)	87.1° 15:20	10.95	96%	110.7°
2027-11-16 Tue	61	—	unknown	18:40–21:05 (good, 2.42 h)	87.1° 15:15	10.98	90%	114.4°
2027-11-17 Wed	63	—	unknown	18:40–21:05 (good, 2.42 h)	87.1° 15:15	11.01	83%	116.5°
2027-11-18 Thu	63	—	unknown	18:40–21:10 (good, 2.5 h)	87.1° 15:10	11.04	73%	116.9°
2027-11-19 Fri	62	—	unknown	18:35–21:05 (good, 2.5 h)	87.1° 15:05	11.06	63%	115.5°
2027-11-20 Sat	61	—	unknown	18:35–21:00 (good, 2.42 h)	87.1° 15:00	11.09	51%	112.6°
2027-11-21 Sun	59	—	unknown	18:35–20:55 (good, 2.33 h)	87.1° 15:00	11.11	40%	108.3°
2027-11-22 Mon	57	—	unknown	18:35–20:55 (good, 2.33 h)	87.1° 14:55	11.14	29%	103.0°
2027-11-23 Tue	56	—	unknown	18:35–20:50 (good, 2.25 h)	87.1° 14:50	11.16	20%	97.1°
2027-11-24 Wed	54	—	unknown	18:35–20:45 (good, 2.17 h)	87.1° 14:45	11.19	12%	90.9°
2027-11-25 Thu	53	—	unknown	18:35–20:40 (good, 2.08 h)	87.1° 14:40	11.21	6%	84.8°
2027-11-26 Fri	52	—	unknown	18:35–20:35 (good, 2.0 h)	87.1° 14:40	11.23	2%	79.0°
2027-11-27 Sat	50	—	unknown	18:35–20:35 (good, 2.0 h)	87.1° 14:35	11.25	0%	73.8°
2027-11-28 Sun	48	—	unknown	18:35–20:30 (good, 1.92 h)	87.1° 14:30	11.27	1%	69.4°
2027-11-29 Mon	46	—	unknown	18:35–20:25 (good, 1.83 h)	87.1° 14:25	11.29	3%	66.0°
2027-11-30 Tue	45	—	unknown	18:35–20:20 (good, 1.75 h)	87.1° 14:20	11.31	8%	63.8°
2027-12-01 Wed	41	—	unknown	18:35–20:20 (good, 1.75 h)	87.1° 14:20	11.33	14%	63.0°
2027-12-02 Thu	36	—	unknown	18:35–20:05 (good, 1.5 h)	87.1° 14:15	11.34	21%	63.4°
2027-12-03 Fri	32	—	unknown	18:35–20:00 (good, 1.42 h)	87.1° 14:10	11.36	29%	65.0°
2027-12-04 Sat	28	—	unknown	18:35–19:50 (good, 1.25 h)	87.1° 14:05	11.38	38%	67.7°
2027-12-05 Sun	24	—	unknown	18:35–19:40 (good, 1.08 h)	87.1° 14:05	11.39	47%	71.4°
2027-12-06 Mon	21	—	unknown	18:35–19:30 (good, 0.92 h)	87.1° 14:00	11.4	57%	75.8°
2027-12-07 Tue	19	—	unknown	18:35–19:15 (good, 0.67 h)	87.1° 13:55	11.42	66%	80.9°
2027-12-08 Wed	18	—	unknown	18:35–19:00 (good, 0.42 h)	87.1° 13:50	11.43	75%	86.4°
2027-12-09 Thu	17	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 13:45	11.44	83%	92.2°
2027-12-10 Fri	17	—	unknown	18:35–19:05 (good, 0.5 h)	87.1° 13:45	11.45	90%	98.1°
2027-12-11 Sat	18	—	unknown	18:35–19:10 (good, 0.58 h)	87.1° 13:40	11.46	96%	103.8°
2027-12-12 Sun	19	—	unknown	18:35–19:15 (good, 0.67 h)	87.1° 13:35	11.47	99%	109.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2027-11-13&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.