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: 09-27 (100), 09-28 (100), 09-29 (100), 09-30 (100), 10-01 (100) — by astronomy; check the weather when the night is within four days.

2037-09-25astronomy score per night — click a bar for that night2037-10-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-09-25 Fri	78	—	unknown	20:50–00:45 (good, 3.92 h)	87.1° 19:40	8.9	98%	96.1°
2037-09-26 Sat	86	—	unknown	20:45–01:05 (good, 4.33 h)	87.1° 19:35	8.95	94%	101.7°
2037-09-27 Sun	100	—	unknown	20:45–01:10 (good, 4.42 h)	87.1° 19:30	9.0	89%	107.0°
2037-09-28 Mon	100	—	unknown	20:45–01:10 (good, 4.42 h)	87.1° 19:30	9.05	83%	111.7°
2037-09-29 Tue	100	—	unknown	20:40–01:10 (good, 4.5 h)	87.1° 19:25	9.1	75%	115.5°
2037-09-30 Wed	100	—	unknown	20:40–01:10 (good, 4.5 h)	87.1° 19:20	9.15	66%	118.2°
2037-10-01 Thu	100	—	unknown	20:35–01:10 (good, 4.58 h)	87.1° 19:15	9.2	55%	119.5°
2037-10-02 Fri	100	—	unknown	20:35–01:10 (good, 4.58 h)	87.1° 19:10	9.24	45%	119.1°
2037-10-03 Sat	100	—	unknown	20:35–01:10 (good, 4.58 h)	87.1° 19:10	9.29	34%	117.0°
2037-10-04 Sun	100	—	unknown	20:30–01:05 (good, 4.58 h)	87.1° 19:05	9.34	24%	113.1°
2037-10-05 Mon	100	—	unknown	20:30–01:00 (good, 4.5 h)	87.1° 19:00	9.38	15%	107.8°
2037-10-06 Tue	100	—	unknown	20:30–00:55 (good, 4.42 h)	87.1° 18:55	9.43	7%	101.3°
2037-10-07 Wed	100	—	unknown	20:25–00:50 (good, 4.42 h)	87.1° 18:55	9.48	2%	94.1°
2037-10-08 Thu	100	—	unknown	20:25–00:50 (good, 4.42 h)	87.1° 18:50	9.52	0%	86.6°
2037-10-09 Fri	100	—	unknown	20:25–00:45 (good, 4.33 h)	87.1° 18:45	9.57	1%	79.4°
2037-10-10 Sat	100	—	unknown	20:20–00:40 (good, 4.33 h)	87.1° 18:40	9.61	5%	72.8°
2037-10-11 Sun	100	—	unknown	20:20–00:35 (good, 4.25 h)	87.1° 18:35	9.66	11%	67.3°
2037-10-12 Mon	99	—	unknown	20:20–00:30 (good, 4.17 h)	87.1° 18:35	9.7	20%	63.3°
2037-10-13 Tue	93	—	unknown	20:15–00:30 (good, 4.25 h)	87.1° 18:30	9.75	29%	61.1°
2037-10-14 Wed	85	—	unknown	20:15–00:25 (good, 4.17 h)	87.1° 18:25	9.79	39%	60.6°
2037-10-15 Thu	73	—	unknown	20:15–00:20 (good, 4.08 h)	87.1° 18:20	9.84	49%	61.7°
2037-10-16 Fri	63	—	unknown	20:15–23:55 (good, 3.67 h)	87.1° 18:15	9.88	59%	64.2°
2037-10-17 Sat	57	—	unknown	20:10–23:45 (good, 3.58 h)	87.1° 18:15	9.92	68%	67.9°
2037-10-18 Sun	53	—	unknown	20:10–23:05 (good, 2.92 h)	87.1° 18:10	9.96	77%	72.4°
2037-10-19 Mon	51	—	unknown	20:10–22:35 (good, 2.42 h)	87.1° 18:05	10.01	84%	77.5°
2037-10-20 Tue	52	—	unknown	20:05–22:25 (good, 2.33 h)	87.1° 18:00	10.05	90%	83.0°
2037-10-21 Wed	54	—	unknown	20:05–22:35 (good, 2.5 h)	87.1° 18:00	10.09	95%	88.8°
2037-10-22 Thu	57	—	unknown	20:05–22:50 (good, 2.75 h)	87.1° 17:55	10.13	98%	94.6°
2037-10-23 Fri	61	—	unknown	20:05–23:10 (good, 3.08 h)	87.1° 17:50	10.17	100%	100.3°
2037-10-24 Sat	67	—	unknown	20:00–23:20 (good, 3.33 h)	87.1° 17:45	10.21	99%	105.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-09-25&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.