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: 07-17 (100), 07-18 (100), 07-19 (100), 07-20 (100), 07-21 (100) — by astronomy; check the weather when the night is within four days.

2042-07-17astronomy score per night — click a bar for that night2042-08-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-07-17 Thu	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:15	5.09	1%	111.9°
2042-07-18 Fri	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:10	5.14	3%	109.5°
2042-07-19 Sat	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:10	5.18	8%	106.2°
2042-07-20 Sun	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:05	5.23	14%	102.3°
2042-07-21 Mon	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 00:00	5.28	21%	98.0°
2042-07-22 Tue	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.33	29%	93.4°
2042-07-23 Wed	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.38	38%	88.7°
2042-07-24 Thu	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:50	5.43	47%	84.1°
2042-07-25 Fri	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:45	5.48	57%	79.7°
2042-07-26 Sat	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:40	5.53	66%	75.6°
2042-07-27 Sun	100	—	unknown	22:45–04:20 (good, 5.58 h)	87.1° 23:35	5.58	75%	72.0°
2042-07-28 Mon	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:35	5.64	84%	69.2°
2042-07-29 Tue	93	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:30	5.69	90%	67.4°
2042-07-30 Wed	85	—	unknown	22:40–04:25 (good, 5.75 h)	87.1° 23:25	5.74	96%	66.7°
2042-07-31 Thu	67	—	unknown	22:35–03:35 (good, 5.0 h)	87.1° 23:20	5.8	99%	67.5°
2042-08-01 Fri	68	—	unknown	22:35–02:40 (good, 4.08 h)	87.1° 23:15	5.85	100%	69.6°
2042-08-02 Sat	72	—	unknown	22:35–02:35 (good, 4.0 h)	87.1° 23:15	5.91	98%	73.1°
2042-08-03 Sun	77	—	unknown	22:30–02:55 (good, 4.42 h)	87.1° 23:10	5.97	93%	77.6°
2042-08-04 Mon	82	—	unknown	22:30–03:35 (good, 5.08 h)	87.1° 23:05	6.02	86%	82.8°
2042-08-05 Tue	100	—	unknown	22:25–04:20 (good, 5.92 h)	87.1° 23:00	6.08	77%	88.4°
2042-08-06 Wed	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.13	67%	94.1°
2042-08-07 Thu	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.19	56%	99.5°
2042-08-08 Fri	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.1° 22:50	6.25	44%	104.2°
2042-08-09 Sat	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:45	6.3	34%	108.2°
2042-08-10 Sun	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.1° 22:40	6.36	24%	111.1°
2042-08-11 Mon	100	—	unknown	22:15–04:35 (good, 6.33 h)	87.1° 22:40	6.42	15%	112.8°
2042-08-12 Tue	100	—	unknown	22:15–04:30 (good, 6.25 h)	87.1° 22:35	6.48	8%	113.2°
2042-08-13 Wed	100	—	unknown	22:15–04:30 (good, 6.25 h)	87.1° 22:30	6.53	4%	112.3°
2042-08-14 Thu	100	—	unknown	22:10–04:25 (good, 6.25 h)	87.1° 22:25	6.59	1%	110.3°
2042-08-15 Fri	100	—	unknown	22:10–04:20 (good, 6.17 h)	87.1° 22:20	6.65	0%	107.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-07-17&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.