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: 09-09 (100), 09-10 (100), 09-11 (100), 09-12 (100), 09-13 (100) — by astronomy; check the weather when the night is within four days.

2037-09-09astronomy score per night — click a bar for that night2037-10-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-09-09 Wed	100	—	unknown	21:20–02:40 (good, 5.33 h)	87.1° 20:45	8.07	0%	98.1°
2037-09-10 Thu	100	—	unknown	21:15–02:40 (good, 5.42 h)	87.1° 20:40	8.12	2%	90.6°
2037-09-11 Fri	100	—	unknown	21:15–02:35 (good, 5.33 h)	87.1° 20:35	8.18	7%	83.2°
2037-09-12 Sat	100	—	unknown	21:15–02:30 (good, 5.25 h)	87.1° 20:30	8.23	15%	76.2°
2037-09-13 Sun	100	—	unknown	21:10–02:25 (good, 5.25 h)	87.1° 20:25	8.28	24%	70.2°
2037-09-14 Mon	100	—	unknown	21:10–02:20 (good, 5.17 h)	87.1° 20:25	8.34	34%	65.4°
2037-09-15 Tue	97	—	unknown	21:05–02:20 (good, 5.25 h)	87.1° 20:20	8.39	45%	62.1°
2037-09-16 Wed	91	—	unknown	21:05–02:15 (good, 5.17 h)	87.1° 20:15	8.44	55%	60.5°
2037-09-17 Thu	84	—	unknown	21:05–02:10 (good, 5.08 h)	87.1° 20:10	8.49	65%	60.5°
2037-09-18 Fri	69	—	unknown	21:00–01:40 (good, 4.67 h)	87.1° 20:05	8.55	74%	62.0°
2037-09-19 Sat	61	—	unknown	21:00–00:45 (good, 3.75 h)	87.1° 20:05	8.6	82%	64.9°
2037-09-20 Sun	58	—	unknown	20:55–23:45 (good, 2.83 h)	87.1° 20:00	8.65	89%	68.8°
2037-09-21 Mon	58	—	unknown	20:55–23:30 (good, 2.58 h)	87.1° 19:55	8.7	94%	73.5°
2037-09-22 Tue	60	—	unknown	20:55–23:30 (good, 2.58 h)	87.1° 19:50	8.75	98%	78.8°
2037-09-23 Wed	65	—	unknown	20:50–23:50 (good, 3.0 h)	87.1° 19:50	8.8	100%	84.5°
2037-09-24 Thu	71	—	unknown	20:50–00:15 (good, 3.42 h)	87.1° 19:45	8.85	100%	90.3°
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°

Download: CSV · JSON

💡 API

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