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: 03-29 (100), 03-30 (100), 03-31 (100), 04-01 (100), 04-02 (100) — by astronomy; check the weather when the night is within four days.

2038-03-18astronomy score per night — click a bar for that night2038-04-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-03-18 Thu	69	—	unknown	01:40–04:55 (good, 3.25 h)	87.1° 07:10	8.82	93%	107.1°
2038-03-19 Fri	61	—	unknown	01:45–04:55 (good, 3.17 h)	87.1° 07:10	8.77	98%	100.8°
2038-03-20 Sat	53	—	unknown	02:25–04:50 (good, 2.42 h)	87.1° 07:05	8.72	100%	93.7°
2038-03-21 Sun	48	—	unknown	02:55–04:50 (good, 1.92 h)	87.1° 07:00	8.67	99%	86.4°
2038-03-22 Mon	45	—	unknown	03:15–04:50 (good, 1.58 h)	87.1° 06:55	8.61	95%	79.3°
2038-03-23 Tue	44	—	unknown	03:05–04:45 (good, 1.67 h)	87.1° 06:50	8.56	88%	72.9°
2038-03-24 Wed	48	—	unknown	02:20–04:45 (good, 2.42 h)	87.1° 06:50	8.51	79%	67.6°
2038-03-25 Thu	54	—	unknown	01:15–04:45 (good, 3.5 h)	87.1° 06:45	8.46	69%	63.8°
2038-03-26 Fri	67	—	unknown	00:45–04:40 (good, 3.92 h)	87.1° 06:40	8.4	59%	61.7°
2038-03-27 Sat	82	—	unknown	00:40–05:40 (good, 4.0 h)	87.1° 07:35	8.35	48%	61.3°
2038-03-28 Sun	93	—	unknown	01:40–05:35 (good, 3.92 h)	87.1° 07:35	8.3	38%	62.6°
2038-03-29 Mon	100	—	unknown	01:35–05:35 (good, 4.0 h)	87.1° 07:30	8.24	28%	65.2°
2038-03-30 Tue	100	—	unknown	01:30–05:35 (good, 4.08 h)	87.1° 07:25	8.19	20%	69.0°
2038-03-31 Wed	100	—	unknown	01:25–05:30 (good, 4.08 h)	87.1° 07:20	8.13	12%	73.6°
2038-04-01 Thu	100	—	unknown	01:20–05:30 (good, 4.17 h)	87.1° 07:15	8.08	7%	78.7°
2038-04-02 Fri	100	—	unknown	01:20–05:25 (good, 4.08 h)	87.1° 07:15	8.02	3%	84.3°
2038-04-03 Sat	100	—	unknown	01:15–05:25 (good, 4.17 h)	87.1° 07:10	7.97	1%	89.9°
2038-04-04 Sun	100	—	unknown	01:10–05:25 (good, 4.25 h)	87.1° 07:05	7.91	0%	95.6°
2038-04-05 Mon	100	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 07:00	7.86	2%	101.0°
2038-04-06 Tue	100	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 06:55	7.8	5%	106.1°
2038-04-07 Wed	100	—	unknown	01:00–05:20 (good, 4.33 h)	87.1° 06:55	7.74	9%	110.6°
2038-04-08 Thu	100	—	unknown	00:55–05:15 (good, 4.33 h)	87.1° 06:50	7.69	16%	114.3°
2038-04-09 Fri	100	—	unknown	00:50–05:15 (good, 4.42 h)	87.1° 06:45	7.63	23%	117.0°
2038-04-10 Sat	100	—	unknown	00:50–05:10 (good, 4.33 h)	87.1° 06:40	7.57	32%	118.4°
2038-04-11 Sun	100	—	unknown	00:50–05:10 (good, 4.33 h)	87.1° 06:35	7.52	42%	118.4°
2038-04-12 Mon	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:35	7.46	52%	116.8°
2038-04-13 Tue	100	—	unknown	00:45–05:05 (good, 4.33 h)	87.1° 06:30	7.4	62%	113.7°
2038-04-14 Wed	100	—	unknown	00:45–05:05 (good, 4.33 h)	87.1° 06:25	7.35	73%	109.2°
2038-04-15 Thu	88	—	unknown	00:50–05:00 (good, 4.17 h)	87.1° 06:20	7.29	82%	103.5°
2038-04-16 Fri	78	—	unknown	01:00–05:00 (good, 4.0 h)	87.1° 06:20	7.23	90%	96.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-03-18&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.