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: 02-13 (58), 02-12 (57), 02-11 (52), 02-10 (47), 02-09 (42) — by astronomy; check the weather when the night is within four days.

2045-01-15astronomy score per night — click a bar for that night2045-02-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-01-15 Sun	24	—	unknown	05:20–06:10 (good, 0.83 h)	87.1° 11:15	11.22	5%	67.0°
2045-01-16 Mon	25	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 11:10	11.19	2%	65.6°
2045-01-17 Tue	27	—	unknown	05:10–06:10 (good, 1.0 h)	87.1° 11:05	11.17	0%	65.3°
2045-01-18 Wed	28	—	unknown	05:10–06:10 (good, 1.0 h)	87.1° 11:05	11.15	0%	66.1°
2045-01-19 Thu	29	—	unknown	05:05–06:10 (good, 1.08 h)	87.1° 11:00	11.12	3%	67.9°
2045-01-20 Fri	30	—	unknown	05:00–06:10 (good, 1.17 h)	87.1° 10:55	11.1	7%	70.8°
2045-01-21 Sat	31	—	unknown	04:55–06:05 (good, 1.17 h)	87.1° 10:50	11.07	12%	74.4°
2045-01-22 Sun	32	—	unknown	04:55–06:05 (good, 1.17 h)	87.1° 10:45	11.05	19%	78.8°
2045-01-23 Mon	34	—	unknown	04:50–06:05 (good, 1.25 h)	87.1° 10:45	11.02	27%	83.6°
2045-01-24 Tue	34	—	unknown	04:45–06:05 (good, 1.33 h)	87.1° 10:40	10.99	37%	88.8°
2045-01-25 Wed	36	—	unknown	04:40–06:05 (good, 1.42 h)	87.1° 10:35	10.96	47%	94.2°
2045-01-26 Thu	37	—	unknown	04:35–06:05 (good, 1.5 h)	87.1° 10:30	10.93	58%	99.5°
2045-01-27 Fri	39	—	unknown	04:35–06:05 (good, 1.5 h)	87.1° 10:25	10.9	68%	104.6°
2045-01-28 Sat	40	—	unknown	04:35–06:05 (good, 1.5 h)	87.1° 10:25	10.87	78%	109.0°
2045-01-29 Sun	37	—	unknown	04:35–06:00 (good, 1.42 h)	87.1° 10:20	10.84	87%	112.4°
2045-01-30 Mon	33	—	unknown	04:35–06:00 (good, 1.42 h)	87.1° 10:15	10.81	94%	114.4°
2045-01-31 Tue	33	—	unknown	04:35–06:00 (good, 1.42 h)	87.1° 10:10	10.78	99%	114.6°
2045-02-01 Wed	32	—	unknown	04:30–06:00 (good, 1.5 h)	87.1° 10:10	10.74	100%	112.9°
2045-02-02 Thu	31	—	unknown	04:30–06:00 (good, 1.5 h)	87.1° 10:05	10.71	98%	109.7°
2045-02-03 Fri	30	—	unknown	04:30–05:55 (good, 1.42 h)	87.1° 10:00	10.68	94%	105.2°
2045-02-04 Sat	30	—	unknown	04:30–05:55 (good, 1.42 h)	87.1° 09:55	10.64	87%	99.9°
2045-02-05 Sun	31	—	unknown	04:25–05:55 (good, 1.5 h)	87.1° 09:50	10.61	78%	94.2°
2045-02-06 Mon	32	—	unknown	04:15–05:55 (good, 1.67 h)	87.1° 09:50	10.57	69%	88.6°
2045-02-07 Tue	35	—	unknown	04:10–05:55 (good, 1.75 h)	87.1° 09:45	10.54	59%	83.2°
2045-02-08 Wed	38	—	unknown	04:00–05:50 (good, 1.83 h)	87.1° 09:40	10.5	48%	78.3°
2045-02-09 Thu	42	—	unknown	03:55–05:50 (good, 1.92 h)	87.1° 09:35	10.46	39%	73.9°
2045-02-10 Fri	47	—	unknown	03:40–05:50 (good, 2.17 h)	87.1° 09:30	10.42	30%	70.3°
2045-02-11 Sat	52	—	unknown	03:35–05:50 (good, 2.25 h)	87.1° 09:30	10.39	21%	67.6°
2045-02-12 Sun	57	—	unknown	03:30–05:50 (good, 2.33 h)	87.1° 09:25	10.35	14%	65.9°
2045-02-13 Mon	58	—	unknown	03:25–05:45 (good, 2.33 h)	87.1° 09:20	10.31	8%	65.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-01-15&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.