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), 03-26 (100), 03-27 (100) — by astronomy; check the weather when the night is within four days.

2042-03-13astronomy score per night — click a bar for that night2042-04-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-03-13 Thu	59	—	unknown	01:55–05:05 (good, 3.17 h)	87.1° 07:30	9.07	60%	70.4°
2042-03-14 Fri	68	—	unknown	01:35–05:05 (good, 3.5 h)	87.1° 07:30	9.02	50%	68.1°
2042-03-15 Sat	78	—	unknown	01:30–05:00 (good, 3.5 h)	87.1° 07:25	8.97	40%	66.9°
2042-03-16 Sun	88	—	unknown	01:25–05:00 (good, 3.58 h)	87.1° 07:20	8.92	30%	67.0°
2042-03-17 Mon	94	—	unknown	01:20–04:55 (good, 3.58 h)	87.1° 07:15	8.87	20%	68.6°
2042-03-18 Tue	95	—	unknown	01:20–04:55 (good, 3.58 h)	87.1° 07:10	8.82	11%	71.5°
2042-03-19 Wed	97	—	unknown	01:15–04:55 (good, 3.67 h)	87.1° 07:10	8.77	5%	75.7°
2042-03-20 Thu	97	—	unknown	01:10–04:50 (good, 3.67 h)	87.1° 07:05	8.72	1%	80.9°
2042-03-21 Fri	98	—	unknown	01:05–04:50 (good, 3.75 h)	87.1° 07:00	8.66	0%	86.6°
2042-03-22 Sat	99	—	unknown	01:00–04:50 (good, 3.83 h)	87.1° 06:55	8.61	2%	92.6°
2042-03-23 Sun	100	—	unknown	01:00–04:45 (good, 3.75 h)	87.1° 06:50	8.56	7%	98.4°
2042-03-24 Mon	100	—	unknown	00:55–04:45 (good, 3.83 h)	87.1° 06:50	8.51	15%	103.5°
2042-03-25 Tue	100	—	unknown	00:50–04:45 (good, 3.92 h)	87.1° 06:45	8.45	24%	107.7°
2042-03-26 Wed	100	—	unknown	00:50–04:40 (good, 3.83 h)	87.1° 06:40	8.4	34%	110.8°
2042-03-27 Thu	100	—	unknown	00:50–04:40 (good, 3.83 h)	87.1° 06:35	8.35	44%	112.6°
2042-03-28 Fri	100	—	unknown	00:45–04:35 (good, 3.83 h)	87.1° 06:35	8.29	55%	113.1°
2042-03-29 Sat	99	—	unknown	00:45–05:35 (good, 3.83 h)	87.1° 07:30	8.24	64%	112.5°
2042-03-30 Sun	96	—	unknown	01:45–05:35 (good, 3.83 h)	87.1° 07:25	8.18	74%	110.8°
2042-03-31 Mon	84	—	unknown	01:45–05:30 (good, 3.75 h)	87.1° 07:20	8.13	82%	108.1°
2042-04-01 Tue	79	—	unknown	01:45–05:30 (good, 3.75 h)	87.1° 07:15	8.08	88%	104.8°
2042-04-02 Wed	72	—	unknown	01:50–05:25 (good, 3.58 h)	87.1° 07:15	8.02	94%	100.8°
2042-04-03 Thu	66	—	unknown	02:05–05:25 (good, 3.33 h)	87.1° 07:10	7.97	98%	96.5°
2042-04-04 Fri	62	—	unknown	02:30–05:25 (good, 2.92 h)	87.1° 07:05	7.91	100%	91.9°
2042-04-05 Sat	57	—	unknown	02:45–05:20 (good, 2.58 h)	87.1° 07:00	7.85	100%	87.3°
2042-04-06 Sun	55	—	unknown	02:55–05:20 (good, 2.42 h)	87.1° 06:55	7.8	98%	82.7°
2042-04-07 Mon	54	—	unknown	02:45–05:15 (good, 2.5 h)	87.1° 06:55	7.74	95%	78.4°
2042-04-08 Tue	55	—	unknown	02:15–05:15 (good, 3.0 h)	87.1° 06:50	7.69	90%	74.5°
2042-04-09 Wed	59	—	unknown	01:20–05:15 (good, 3.92 h)	87.1° 06:45	7.63	83%	71.2°
2042-04-10 Thu	73	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:40	7.57	75%	68.7°
2042-04-11 Fri	87	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:35	7.52	66%	67.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-03-13&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.