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: 02-03 (47), 02-04 (46), 02-02 (45), 02-01 (43), 01-31 (42) — by astronomy; check the weather when the night is within four days.

2039-01-06astronomy score per night — click a bar for that night2039-02-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-01-06 Thu	13	—	unknown	06:00–06:10 (good, 0.17 h)	87.1° 11:50	11.39	88%	113.8°
2039-01-07 Fri	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:50	11.38	94%	116.2°
2039-01-08 Sat	12	—	unknown	06:00–06:10 (good, 0.17 h)	87.1° 11:45	11.36	98%	117.3°
2039-01-09 Sun	13	—	unknown	06:00–06:10 (good, 0.17 h)	87.1° 11:40	11.34	100%	117.2°
2039-01-10 Mon	13	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:35	11.33	100%	115.6°
2039-01-11 Tue	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:30	11.31	98%	112.7°
2039-01-12 Wed	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:30	11.29	94%	108.6°
2039-01-13 Thu	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:25	11.27	88%	103.6°
2039-01-14 Fri	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:20	11.25	80%	97.8°
2039-01-15 Sat	14	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:15	11.23	70%	91.7°
2039-01-16 Sun	16	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:15	11.21	59%	85.4°
2039-01-17 Mon	17	—	unknown	05:35–06:10 (good, 0.58 h)	87.1° 11:10	11.18	48%	79.2°
2039-01-18 Tue	20	—	unknown	05:25–06:10 (good, 0.75 h)	87.1° 11:05	11.16	37%	73.4°
2039-01-19 Wed	23	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 11:00	11.14	26%	68.6°
2039-01-20 Thu	27	—	unknown	05:05–06:10 (good, 1.08 h)	87.1° 10:55	11.11	17%	65.0°
2039-01-21 Fri	30	—	unknown	05:00–06:05 (good, 1.08 h)	87.1° 10:55	11.09	9%	62.9°
2039-01-22 Sat	31	—	unknown	04:55–06:05 (good, 1.17 h)	87.1° 10:50	11.06	4%	62.8°
2039-01-23 Sun	33	—	unknown	04:50–06:05 (good, 1.25 h)	87.1° 10:45	11.03	1%	64.4°
2039-01-24 Mon	34	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:40	11.01	0%	67.6°
2039-01-25 Tue	36	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:35	10.98	2%	72.0°
2039-01-26 Wed	37	—	unknown	04:40–06:05 (good, 1.42 h)	87.1° 10:35	10.95	7%	77.2°
2039-01-27 Thu	38	—	unknown	04:35–06:05 (good, 1.5 h)	87.1° 10:30	10.92	13%	82.8°
2039-01-28 Fri	39	—	unknown	04:30–06:05 (good, 1.58 h)	87.1° 10:25	10.89	20%	88.6°
2039-01-29 Sat	40	—	unknown	04:25–06:00 (good, 1.58 h)	87.1° 10:20	10.86	29%	94.3°
2039-01-30 Sun	41	—	unknown	04:25–06:00 (good, 1.58 h)	87.1° 10:20	10.83	38%	99.7°
2039-01-31 Mon	42	—	unknown	04:20–06:00 (good, 1.67 h)	87.1° 10:15	10.79	48%	104.6°
2039-02-01 Tue	43	—	unknown	04:15–06:00 (good, 1.75 h)	87.1° 10:10	10.76	57%	109.0°
2039-02-02 Wed	45	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:05	10.73	66%	112.7°
2039-02-03 Thu	47	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:00	10.7	75%	115.4°
2039-02-04 Fri	46	—	unknown	04:10–05:55 (good, 1.75 h)	87.1° 10:00	10.66	83%	117.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-01-06&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.