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

2046-03-28astronomy score per night — click a bar for that night2046-04-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-03-28 Wed	80	—	unknown	01:40–05:35 (good, 3.92 h)	87.1° 07:35	8.29	54%	65.4°
2046-03-29 Thu	90	—	unknown	01:35–05:35 (good, 4.0 h)	87.1° 07:30	8.24	44%	63.9°
2046-03-30 Fri	97	—	unknown	01:30–05:35 (good, 4.08 h)	87.1° 07:25	8.18	34%	63.7°
2046-03-31 Sat	100	—	unknown	01:25–05:30 (good, 4.08 h)	87.1° 07:20	8.13	25%	64.8°
2046-04-01 Sun	100	—	unknown	01:20–05:30 (good, 4.17 h)	87.1° 07:15	8.07	18%	67.0°
2046-04-02 Mon	100	—	unknown	01:20–05:25 (good, 4.08 h)	87.1° 07:15	8.02	11%	70.2°
2046-04-03 Tue	100	—	unknown	01:15–05:25 (good, 4.17 h)	87.1° 07:10	7.96	6%	74.1°
2046-04-04 Wed	100	—	unknown	01:10–05:25 (good, 4.25 h)	87.1° 07:05	7.91	2%	78.7°
2046-04-05 Thu	100	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 07:00	7.85	0%	83.7°
2046-04-06 Fri	100	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 06:55	7.8	0%	89.0°
2046-04-07 Sat	100	—	unknown	01:00–05:15 (good, 4.25 h)	87.1° 06:55	7.74	2%	94.4°
2046-04-08 Sun	100	—	unknown	00:55–05:15 (good, 4.33 h)	87.1° 06:50	7.68	6%	99.7°
2046-04-09 Mon	100	—	unknown	00:50–05:15 (good, 4.42 h)	87.1° 06:45	7.63	11%	104.7°
2046-04-10 Tue	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:40	7.57	18%	109.2°
2046-04-11 Wed	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:35	7.51	27%	112.8°
2046-04-12 Thu	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:35	7.46	37%	115.3°
2046-04-13 Fri	100	—	unknown	00:40–05:05 (good, 4.42 h)	87.1° 06:30	7.4	48%	116.4°
2046-04-14 Sat	100	—	unknown	00:40–05:05 (good, 4.42 h)	87.1° 06:25	7.34	59%	116.0°
2046-04-15 Sun	100	—	unknown	00:40–05:00 (good, 4.33 h)	87.1° 06:20	7.28	70%	113.9°
2046-04-16 Mon	100	—	unknown	00:40–05:00 (good, 4.33 h)	87.1° 06:20	7.23	80%	110.2°
2046-04-17 Tue	100	—	unknown	00:40–05:00 (good, 4.33 h)	87.1° 06:15	7.17	88%	105.1°
2046-04-18 Wed	82	—	unknown	00:45–04:55 (good, 4.17 h)	87.1° 06:10	7.11	95%	99.2°
2046-04-19 Thu	74	—	unknown	01:10–04:55 (good, 3.75 h)	87.1° 06:05	7.05	99%	92.6°
2046-04-20 Fri	67	—	unknown	01:30–04:50 (good, 3.33 h)	87.1° 06:00	6.99	100%	86.0°
2046-04-21 Sat	63	—	unknown	01:35–04:50 (good, 3.25 h)	87.1° 06:00	6.94	98%	79.7°
2046-04-22 Sun	62	—	unknown	01:10–04:50 (good, 3.67 h)	87.1° 05:55	6.88	94%	74.1°
2046-04-23 Mon	65	—	unknown	00:25–04:45 (good, 4.33 h)	87.1° 05:50	6.82	87%	69.5°
2046-04-24 Tue	84	—	unknown	23:50–04:45 (good, 4.92 h)	87.1° 05:45	6.76	79%	66.1°
2046-04-25 Wed	90	—	unknown	23:50–04:40 (good, 4.83 h)	87.1° 05:40	6.7	70%	64.0°
2046-04-26 Thu	95	—	unknown	23:45–04:40 (good, 4.92 h)	87.1° 05:40	6.64	60%	63.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-03-28&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.