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: 03-12 (82), 03-11 (76), 02-25 (72), 02-23 (71), 02-24 (71) — by astronomy; check the weather when the night is within four days.

2045-02-11astronomy score per night — click a bar for that night2045-03-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-02-11 Sat	52	—	unknown	03:35–05:50 (good, 2.25 h)	87.1° 09:30	10.39	21%	67.6°
2045-02-12 Sun	57	—	unknown	03:30–05:50 (good, 2.33 h)	87.1° 09:25	10.35	14%	65.9°
2045-02-13 Mon	58	—	unknown	03:25–05:45 (good, 2.33 h)	87.1° 09:20	10.31	8%	65.3°
2045-02-14 Tue	60	—	unknown	03:20–05:45 (good, 2.42 h)	87.1° 09:15	10.27	4%	65.8°
2045-02-15 Wed	61	—	unknown	03:20–05:45 (good, 2.42 h)	87.1° 09:15	10.23	1%	67.4°
2045-02-16 Thu	63	—	unknown	03:15–05:45 (good, 2.5 h)	87.1° 09:10	10.19	0%	70.0°
2045-02-17 Fri	63	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:05	10.15	1%	73.4°
2045-02-18 Sat	64	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 09:00	10.11	4%	77.6°
2045-02-19 Sun	66	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 08:55	10.07	8%	82.4°
2045-02-20 Mon	68	—	unknown	03:00–05:40 (good, 2.67 h)	87.1° 08:55	10.02	14%	87.5°
2045-02-21 Tue	68	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:50	9.98	22%	92.8°
2045-02-22 Wed	69	—	unknown	02:50–05:35 (good, 2.75 h)	87.1° 08:45	9.94	32%	98.1°
2045-02-23 Thu	71	—	unknown	02:45–05:35 (good, 2.83 h)	87.1° 08:40	9.9	42%	103.2°
2045-02-24 Fri	71	—	unknown	02:45–05:30 (good, 2.75 h)	87.1° 08:35	9.85	53%	107.7°
2045-02-25 Sat	72	—	unknown	02:45–05:30 (good, 2.75 h)	87.1° 08:35	9.81	64%	111.3°
2045-02-26 Sun	70	—	unknown	02:45–05:30 (good, 2.75 h)	87.1° 08:30	9.76	74%	113.8°
2045-02-27 Mon	68	—	unknown	02:45–05:25 (good, 2.67 h)	87.1° 08:25	9.72	84%	114.7°
2045-02-28 Tue	61	—	unknown	02:45–05:25 (good, 2.67 h)	87.1° 08:20	9.67	92%	113.9°
2045-03-01 Wed	58	—	unknown	02:45–05:25 (good, 2.67 h)	87.1° 08:20	9.63	97%	111.4°
2045-03-02 Thu	54	—	unknown	02:45–05:25 (good, 2.67 h)	87.1° 08:15	9.58	100%	107.4°
2045-03-03 Fri	51	—	unknown	02:45–05:20 (good, 2.58 h)	87.1° 08:10	9.54	99%	102.4°
2045-03-04 Sat	48	—	unknown	02:50–05:20 (good, 2.5 h)	87.1° 08:05	9.49	96%	96.8°
2045-03-05 Sun	48	—	unknown	02:50–05:20 (good, 2.5 h)	87.1° 08:00	9.44	91%	91.0°
2045-03-06 Mon	48	—	unknown	02:35–05:15 (good, 2.67 h)	87.1° 08:00	9.4	84%	85.3°
2045-03-07 Tue	50	—	unknown	02:25–05:15 (good, 2.83 h)	87.1° 07:55	9.35	75%	80.0°
2045-03-08 Wed	54	—	unknown	02:15–05:15 (good, 3.0 h)	87.1° 07:50	9.3	66%	75.3°
2045-03-09 Thu	60	—	unknown	02:10–05:10 (good, 3.0 h)	87.1° 07:45	9.25	56%	71.4°
2045-03-10 Fri	67	—	unknown	01:50–05:10 (good, 3.33 h)	87.1° 07:40	9.2	46%	68.3°
2045-03-11 Sat	76	—	unknown	01:45–05:10 (good, 3.42 h)	87.1° 07:40	9.16	37%	66.3°
2045-03-12 Sun	82	—	unknown	01:40–05:05 (good, 3.42 h)	87.1° 07:35	9.11	28%	65.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-02-11&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.