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: 03-16 (94), 03-17 (93), 03-14 (92), 03-15 (92), 03-13 (91) — by astronomy; check the weather when the night is within four days.

2043-02-16astronomy score per night — click a bar for that night2043-03-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-02-16 Mon	62	—	unknown	03:15–05:45 (good, 2.5 h)	87.1° 09:10	10.21	53%	106.1°
2043-02-17 Tue	62	—	unknown	03:15–05:40 (good, 2.42 h)	87.1° 09:05	10.17	64%	109.6°
2043-02-18 Wed	62	—	unknown	03:20–05:40 (good, 2.33 h)	87.1° 09:05	10.13	74%	112.0°
2043-02-19 Thu	60	—	unknown	03:15–05:40 (good, 2.42 h)	87.1° 09:00	10.09	83%	113.1°
2043-02-20 Fri	53	—	unknown	03:15–05:40 (good, 2.42 h)	87.1° 08:55	10.05	90%	112.8°
2043-02-21 Sat	50	—	unknown	03:15–05:35 (good, 2.33 h)	87.1° 08:50	10.0	96%	111.2°
2043-02-22 Sun	48	—	unknown	03:15–05:35 (good, 2.33 h)	87.1° 08:45	9.96	99%	108.6°
2043-02-23 Mon	46	—	unknown	03:15–05:35 (good, 2.33 h)	87.1° 08:45	9.92	100%	105.0°
2043-02-24 Tue	43	—	unknown	03:20–05:35 (good, 2.25 h)	87.1° 08:40	9.88	99%	100.8°
2043-02-25 Wed	41	—	unknown	03:30–05:30 (good, 2.0 h)	87.1° 08:35	9.83	96%	96.3°
2043-02-26 Thu	41	—	unknown	03:30–05:30 (good, 2.0 h)	87.1° 08:30	9.79	91%	91.6°
2043-02-27 Fri	42	—	unknown	03:20–05:30 (good, 2.17 h)	87.1° 08:30	9.74	85%	86.9°
2043-02-28 Sat	43	—	unknown	03:00–05:25 (good, 2.42 h)	87.1° 08:25	9.7	78%	82.3°
2043-03-01 Sun	46	—	unknown	02:50–05:25 (good, 2.58 h)	87.1° 08:20	9.65	70%	78.1°
2043-03-02 Mon	51	—	unknown	02:40–05:25 (good, 2.75 h)	87.1° 08:15	9.61	60%	74.3°
2043-03-03 Tue	56	—	unknown	02:30–05:20 (good, 2.83 h)	87.1° 08:10	9.56	51%	71.2°
2043-03-04 Wed	64	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 08:10	9.51	41%	68.8°
2043-03-05 Thu	72	—	unknown	02:10–05:20 (good, 3.17 h)	87.1° 08:05	9.47	32%	67.3°
2043-03-06 Fri	79	—	unknown	02:05–05:15 (good, 3.17 h)	87.1° 08:00	9.42	23%	67.0°
2043-03-07 Sat	84	—	unknown	02:00–05:15 (good, 3.25 h)	87.1° 07:55	9.37	15%	67.8°
2043-03-08 Sun	86	—	unknown	02:00–05:15 (good, 3.25 h)	87.1° 07:50	9.33	8%	70.0°
2043-03-09 Mon	86	—	unknown	01:55–05:10 (good, 3.25 h)	87.1° 07:50	9.28	3%	73.4°
2043-03-10 Tue	88	—	unknown	01:50–05:10 (good, 3.33 h)	87.1° 07:45	9.23	0%	77.8°
2043-03-11 Wed	89	—	unknown	01:45–05:10 (good, 3.42 h)	87.1° 07:40	9.18	0%	83.1°
2043-03-12 Thu	89	—	unknown	01:40–05:05 (good, 3.42 h)	87.1° 07:35	9.13	3%	88.8°
2043-03-13 Fri	91	—	unknown	01:40–05:05 (good, 3.42 h)	87.1° 07:30	9.08	9%	94.5°
2043-03-14 Sat	92	—	unknown	01:35–05:05 (good, 3.5 h)	87.1° 07:30	9.03	17%	100.0°
2043-03-15 Sun	92	—	unknown	01:30–05:00 (good, 3.5 h)	87.1° 07:25	8.98	27%	104.8°
2043-03-16 Mon	94	—	unknown	01:25–05:00 (good, 3.58 h)	87.1° 07:20	8.93	38%	108.7°
2043-03-17 Tue	93	—	unknown	01:30–05:00 (good, 3.5 h)	87.1° 07:15	8.88	49%	111.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-02-16&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.