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: 04-05 (100), 04-06 (100), 04-07 (100), 04-08 (100), 04-09 (100) — by astronomy; check the weather when the night is within four days.

2040-03-14astronomy score per night — click a bar for that night2040-04-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2040-03-14 Wed	92	—	unknown	01:30–05:00 (good, 3.5 h)	87.1° 07:25	9.0	4%	94.8°
2040-03-15 Thu	94	—	unknown	01:25–05:00 (good, 3.58 h)	87.1° 07:20	8.95	10%	100.2°
2040-03-16 Fri	95	—	unknown	01:25–05:00 (good, 3.58 h)	87.1° 07:20	8.9	16%	105.1°
2040-03-17 Sat	94	—	unknown	01:20–04:55 (good, 3.58 h)	87.1° 07:15	8.84	24%	109.1°
2040-03-18 Sun	96	—	unknown	01:15–04:55 (good, 3.67 h)	87.1° 07:10	8.79	33%	112.2°
2040-03-19 Mon	97	—	unknown	01:15–04:55 (good, 3.67 h)	87.1° 07:05	8.74	42%	114.3°
2040-03-20 Tue	96	—	unknown	01:15–04:50 (good, 3.58 h)	87.1° 07:00	8.69	52%	115.3°
2040-03-21 Wed	96	—	unknown	01:10–04:50 (good, 3.67 h)	87.1° 07:00	8.64	61%	115.1°
2040-03-22 Thu	92	—	unknown	01:10–04:45 (good, 3.58 h)	87.1° 06:55	8.59	70%	113.8°
2040-03-23 Fri	90	—	unknown	01:10–04:45 (good, 3.58 h)	87.1° 06:50	8.53	78%	111.4°
2040-03-24 Sat	77	—	unknown	01:10–05:45 (good, 3.58 h)	87.1° 07:45	8.48	86%	108.0°
2040-03-25 Sun	71	—	unknown	02:15–05:40 (good, 3.42 h)	87.1° 07:40	8.43	92%	103.7°
2040-03-26 Mon	65	—	unknown	02:25–05:40 (good, 3.25 h)	87.1° 07:40	8.37	97%	98.8°
2040-03-27 Tue	58	—	unknown	02:55–05:40 (good, 2.75 h)	87.1° 07:35	8.32	99%	93.4°
2040-03-28 Wed	53	—	unknown	03:20–05:35 (good, 2.25 h)	87.1° 07:30	8.27	100%	87.7°
2040-03-29 Thu	50	—	unknown	03:35–05:35 (good, 2.0 h)	87.1° 07:25	8.21	98%	82.1°
2040-03-30 Fri	48	—	unknown	03:35–05:30 (good, 1.92 h)	87.1° 07:25	8.16	94%	76.7°
2040-03-31 Sat	50	—	unknown	03:05–05:30 (good, 2.42 h)	87.1° 07:20	8.1	87%	71.9°
2040-04-01 Sun	55	—	unknown	01:50–05:30 (good, 3.67 h)	87.1° 07:15	8.05	79%	68.1°
2040-04-02 Mon	67	—	unknown	01:15–05:25 (good, 4.17 h)	87.1° 07:10	7.99	68%	65.7°
2040-04-03 Tue	85	—	unknown	01:15–05:25 (good, 4.17 h)	87.1° 07:05	7.94	57%	64.8°
2040-04-04 Wed	95	—	unknown	01:10–05:20 (good, 4.17 h)	87.1° 07:05	7.88	46%	65.5°
2040-04-05 Thu	100	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 07:00	7.83	35%	67.8°
2040-04-06 Fri	100	—	unknown	01:00–05:20 (good, 4.33 h)	87.1° 06:55	7.77	24%	71.4°
2040-04-07 Sat	100	—	unknown	00:55–05:15 (good, 4.33 h)	87.1° 06:50	7.72	16%	76.0°
2040-04-08 Sun	100	—	unknown	00:55–05:15 (good, 4.33 h)	87.1° 06:45	7.66	8%	81.3°
2040-04-09 Mon	100	—	unknown	00:50–05:15 (good, 4.42 h)	87.1° 06:45	7.6	3%	87.0°
2040-04-10 Tue	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:40	7.55	1%	92.7°
2040-04-11 Wed	100	—	unknown	00:40–05:10 (good, 4.5 h)	87.1° 06:35	7.49	0%	98.2°
2040-04-12 Thu	100	—	unknown	00:35–05:05 (good, 4.5 h)	87.1° 06:30	7.43	2%	103.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2040-03-14&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.