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: 03-19 (96), 03-18 (88), 03-17 (80), 03-02 (78), 03-03 (77) — by astronomy; check the weather when the night is within four days.

2031-02-18astronomy score per night — click a bar for that night2031-03-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-02-18 Tue	63	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:05	10.13	10%	58.2°
2031-02-19 Wed	65	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 09:00	10.09	4%	59.6°
2031-02-20 Thu	67	—	unknown	03:00–05:40 (good, 2.67 h)	87.1° 08:55	10.05	1%	63.1°
2031-02-21 Fri	67	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:50	10.01	0%	68.3°
2031-02-22 Sat	69	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:45	9.96	2%	74.5°
2031-02-23 Sun	71	—	unknown	02:50–05:35 (good, 2.75 h)	87.1° 08:45	9.92	7%	81.2°
2031-02-24 Mon	71	—	unknown	02:45–05:35 (good, 2.83 h)	87.1° 08:40	9.88	13%	88.2°
2031-02-25 Tue	72	—	unknown	02:40–05:30 (good, 2.83 h)	87.1° 08:35	9.83	20%	95.0°
2031-02-26 Wed	74	—	unknown	02:35–05:30 (good, 2.92 h)	87.1° 08:30	9.79	29%	101.5°
2031-02-27 Thu	76	—	unknown	02:35–05:30 (good, 2.92 h)	87.1° 08:25	9.75	38%	107.3°
2031-02-28 Fri	75	—	unknown	02:30–05:25 (good, 2.92 h)	87.1° 08:25	9.7	48%	112.5°
2031-03-01 Sat	76	—	unknown	02:25–05:25 (good, 3.0 h)	87.1° 08:20	9.66	57%	116.7°
2031-03-02 Sun	78	—	unknown	02:25–05:25 (good, 3.0 h)	87.1° 08:15	9.61	66%	119.8°
2031-03-03 Mon	77	—	unknown	02:25–05:20 (good, 2.92 h)	87.1° 08:10	9.56	75%	121.6°
2031-03-04 Tue	77	—	unknown	02:25–05:20 (good, 2.92 h)	87.1° 08:10	9.52	83%	121.8°
2031-03-05 Wed	76	—	unknown	02:20–05:20 (good, 3.0 h)	87.1° 08:05	9.47	89%	120.5°
2031-03-06 Thu	67	—	unknown	02:20–05:15 (good, 2.92 h)	87.1° 08:00	9.42	95%	117.7°
2031-03-07 Fri	64	—	unknown	02:20–05:15 (good, 2.92 h)	87.1° 07:55	9.38	98%	113.5°
2031-03-08 Sat	60	—	unknown	02:20–05:15 (good, 2.92 h)	87.1° 07:50	9.33	100%	108.2°
2031-03-09 Sun	55	—	unknown	02:20–05:10 (good, 2.83 h)	87.1° 07:50	9.28	99%	101.9°
2031-03-10 Mon	51	—	unknown	02:35–05:10 (good, 2.58 h)	87.1° 07:45	9.23	96%	95.1°
2031-03-11 Tue	49	—	unknown	02:45–05:10 (good, 2.42 h)	87.1° 07:40	9.18	91%	87.9°
2031-03-12 Wed	47	—	unknown	02:40–05:05 (good, 2.42 h)	87.1° 07:35	9.14	84%	80.7°
2031-03-13 Thu	49	—	unknown	02:10–05:05 (good, 2.92 h)	87.1° 07:30	9.09	75%	73.9°
2031-03-14 Fri	53	—	unknown	02:00–05:05 (good, 3.08 h)	87.1° 07:30	9.04	65%	67.8°
2031-03-15 Sat	60	—	unknown	01:45–05:00 (good, 3.25 h)	87.1° 07:25	8.99	54%	62.8°
2031-03-16 Sun	70	—	unknown	01:25–05:00 (good, 3.58 h)	87.1° 07:20	8.94	42%	59.4°
2031-03-17 Mon	80	—	unknown	01:20–05:00 (good, 3.67 h)	87.1° 07:15	8.89	31%	58.0°
2031-03-18 Tue	88	—	unknown	01:20–04:55 (good, 3.58 h)	87.1° 07:15	8.84	21%	58.8°
2031-03-19 Wed	96	—	unknown	01:15–04:55 (good, 3.67 h)	87.1° 07:10	8.78	13%	61.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-02-18&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.