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: 03-23 (100), 03-24 (100), 03-25 (100), 04-10 (100), 04-11 (100) — by astronomy; check the weather when the night is within four days.

2045-03-17astronomy score per night — click a bar for that night2045-04-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-03-17 Fri	94	—	unknown	01:20–04:55 (good, 3.58 h)	87.1° 07:15	8.86	1%	76.4°
2045-03-18 Sat	96	—	unknown	01:15–04:55 (good, 3.67 h)	87.1° 07:10	8.8	0%	81.1°
2045-03-19 Sun	97	—	unknown	01:15–04:55 (good, 3.67 h)	87.1° 07:05	8.75	2%	86.2°
2045-03-20 Mon	97	—	unknown	01:10–04:50 (good, 3.67 h)	87.1° 07:05	8.7	5%	91.6°
2045-03-21 Tue	98	—	unknown	01:05–04:50 (good, 3.75 h)	87.1° 07:00	8.65	11%	97.0°
2045-03-22 Wed	99	—	unknown	01:00–04:50 (good, 3.83 h)	87.1° 06:55	8.6	18%	102.1°
2045-03-23 Thu	100	—	unknown	00:55–04:45 (good, 3.83 h)	87.1° 06:50	8.54	27%	106.8°
2045-03-24 Fri	100	—	unknown	00:55–04:45 (good, 3.83 h)	87.1° 06:45	8.49	38%	110.6°
2045-03-25 Sat	100	—	unknown	00:55–05:40 (good, 3.75 h)	87.1° 07:45	8.44	49%	113.4°
2045-03-26 Sun	98	—	unknown	01:55–05:40 (good, 3.75 h)	87.1° 07:40	8.39	60%	114.7°
2045-03-27 Mon	97	—	unknown	01:50–05:40 (good, 3.83 h)	87.1° 07:35	8.33	71%	114.4°
2045-03-28 Tue	94	—	unknown	01:50–05:35 (good, 3.75 h)	87.1° 07:30	8.28	81%	112.5°
2045-03-29 Wed	81	—	unknown	01:55–05:35 (good, 3.67 h)	87.1° 07:30	8.22	89%	109.2°
2045-03-30 Thu	74	—	unknown	01:55–05:35 (good, 3.67 h)	87.1° 07:25	8.17	95%	104.6°
2045-03-31 Fri	68	—	unknown	02:00–05:30 (good, 3.5 h)	87.1° 07:20	8.12	99%	99.3°
2045-04-01 Sat	63	—	unknown	02:20–05:30 (good, 3.17 h)	87.1° 07:15	8.06	100%	93.5°
2045-04-02 Sun	59	—	unknown	02:30–05:25 (good, 2.92 h)	87.1° 07:10	8.01	98%	87.6°
2045-04-03 Mon	57	—	unknown	02:25–05:25 (good, 3.0 h)	87.1° 07:10	7.95	94%	82.0°
2045-04-04 Tue	58	—	unknown	01:55–05:25 (good, 3.5 h)	87.1° 07:05	7.89	88%	77.0°
2045-04-05 Wed	61	—	unknown	01:30–05:20 (good, 3.83 h)	87.1° 07:00	7.84	81%	72.6°
2045-04-06 Thu	73	—	unknown	01:00–05:20 (good, 4.33 h)	87.1° 06:55	7.78	72%	69.2°
2045-04-07 Fri	84	—	unknown	01:00–05:15 (good, 4.25 h)	87.1° 06:50	7.73	63%	66.7°
2045-04-08 Sat	93	—	unknown	00:55–05:15 (good, 4.33 h)	87.1° 06:50	7.67	54%	65.4°
2045-04-09 Sun	97	—	unknown	00:50–05:15 (good, 4.42 h)	87.1° 06:45	7.61	44%	65.2°
2045-04-10 Mon	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:40	7.56	35%	66.1°
2045-04-11 Tue	100	—	unknown	00:40–05:10 (good, 4.5 h)	87.1° 06:35	7.5	26%	68.1°
2045-04-12 Wed	100	—	unknown	00:40–05:05 (good, 4.42 h)	87.1° 06:35	7.44	18%	71.1°
2045-04-13 Thu	100	—	unknown	00:35–05:05 (good, 4.5 h)	87.1° 06:30	7.39	12%	74.9°
2045-04-14 Fri	100	—	unknown	00:30–05:05 (good, 4.58 h)	87.1° 06:25	7.33	6%	79.4°
2045-04-15 Sat	100	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:20	7.27	2%	84.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-03-17&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.