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: 02-22 (69), 02-20 (68), 02-21 (68), 02-19 (66), 02-18 (64) — by astronomy; check the weather when the night is within four days.

2045-01-24astronomy score per night — click a bar for that night2045-02-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2045-02-14 Tue	60	—	unknown	03:20–05:45 (good, 2.42 h)	87.1° 09:15	10.27	4%	65.8°
2045-02-15 Wed	61	—	unknown	03:20–05:45 (good, 2.42 h)	87.1° 09:15	10.23	1%	67.4°
2045-02-16 Thu	63	—	unknown	03:15–05:45 (good, 2.5 h)	87.1° 09:10	10.19	0%	70.0°
2045-02-17 Fri	63	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:05	10.15	1%	73.4°
2045-02-18 Sat	64	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 09:00	10.11	4%	77.6°
2045-02-19 Sun	66	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 08:55	10.07	8%	82.4°
2045-02-20 Mon	68	—	unknown	03:00–05:40 (good, 2.67 h)	87.1° 08:55	10.02	14%	87.5°
2045-02-21 Tue	68	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:50	9.98	22%	92.8°
2045-02-22 Wed	69	—	unknown	02:50–05:35 (good, 2.75 h)	87.1° 08:45	9.94	32%	98.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-01-24&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.