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: 03-04 (81), 03-05 (81), 03-02 (80), 03-03 (80), 03-06 (80) — by astronomy; check the weather when the night is within four days.

2028-02-15astronomy score per night — click a bar for that night2028-03-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-02-15 Tue	39	—	unknown	03:45–05:45 (good, 2.0 h)	87.1° 09:15	10.27	65%	83.5°
2028-02-16 Wed	42	—	unknown	03:35–05:45 (good, 2.17 h)	87.1° 09:10	10.23	54%	77.7°
2028-02-17 Thu	47	—	unknown	03:25–05:45 (good, 2.33 h)	87.1° 09:10	10.18	44%	72.7°
2028-02-18 Fri	52	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:05	10.14	34%	68.5°
2028-02-19 Sat	57	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 09:00	10.1	25%	65.4°
2028-02-20 Sun	63	—	unknown	03:00–05:40 (good, 2.67 h)	87.1° 08:55	10.06	17%	63.5°
2028-02-21 Mon	67	—	unknown	03:00–05:35 (good, 2.58 h)	87.1° 08:50	10.02	10%	62.8°
2028-02-22 Tue	69	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:50	9.98	6%	63.4°
2028-02-23 Wed	69	—	unknown	02:50–05:35 (good, 2.75 h)	87.1° 08:45	9.93	2%	65.3°
2028-02-24 Thu	71	—	unknown	02:45–05:35 (good, 2.83 h)	87.1° 08:40	9.89	0%	68.1°
2028-02-25 Fri	72	—	unknown	02:40–05:30 (good, 2.83 h)	87.1° 08:35	9.85	0%	71.9°
2028-02-26 Sat	73	—	unknown	02:40–05:30 (good, 2.83 h)	87.1° 08:30	9.8	2%	76.5°
2028-02-27 Sun	75	—	unknown	02:35–05:30 (good, 2.92 h)	87.1° 08:30	9.76	6%	81.5°
2028-02-28 Mon	75	—	unknown	02:30–05:25 (good, 2.92 h)	87.1° 08:25	9.71	11%	86.9°
2028-02-29 Tue	77	—	unknown	02:25–05:25 (good, 3.0 h)	87.1° 08:20	9.67	18%	92.5°
2028-03-01 Wed	78	—	unknown	02:20–05:25 (good, 3.08 h)	87.1° 08:15	9.62	26%	98.1°
2028-03-02 Thu	80	—	unknown	02:20–05:25 (good, 3.08 h)	87.1° 08:15	9.58	35%	103.4°
2028-03-03 Fri	80	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 08:10	9.53	45%	108.3°
2028-03-04 Sat	81	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 08:05	9.48	56%	112.5°
2028-03-05 Sun	81	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 08:00	9.44	67%	115.6°
2028-03-06 Mon	80	—	unknown	02:10–05:15 (good, 3.08 h)	87.1° 07:55	9.39	77%	117.1°
2028-03-07 Tue	79	—	unknown	02:10–05:15 (good, 3.08 h)	87.1° 07:55	9.34	86%	116.9°
2028-03-08 Wed	69	—	unknown	02:10–05:15 (good, 3.08 h)	87.1° 07:50	9.29	93%	114.7°
2028-03-09 Thu	64	—	unknown	02:10–05:10 (good, 3.0 h)	87.1° 07:45	9.25	98%	110.8°
2028-03-10 Fri	60	—	unknown	02:15–05:10 (good, 2.92 h)	87.1° 07:40	9.2	100%	105.4°
2028-03-11 Sat	55	—	unknown	02:15–05:05 (good, 2.83 h)	87.1° 07:35	9.15	99%	99.1°
2028-03-12 Sun	52	—	unknown	02:25–05:05 (good, 2.67 h)	87.1° 07:35	9.1	95%	92.5°
2028-03-13 Mon	51	—	unknown	02:20–05:05 (good, 2.75 h)	87.1° 07:30	9.05	88%	85.9°
2028-03-14 Tue	52	—	unknown	02:00–05:00 (good, 3.0 h)	87.1° 07:25	9.0	80%	79.6°
2028-03-15 Wed	55	—	unknown	01:50–05:00 (good, 3.17 h)	87.1° 07:20	8.95	70%	74.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-02-15&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.