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: 02-27 (75), 02-26 (74), 02-28 (73), 02-25 (72), 02-23 (71) — by astronomy; check the weather when the night is within four days.

2042-02-03astronomy score per night — click a bar for that night2042-03-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-02-03 Mon	34	—	unknown	04:25–06:00 (good, 1.58 h)	87.1° 10:00	10.69	98%	112.0°
2042-02-04 Tue	33	—	unknown	04:25–05:55 (good, 1.5 h)	87.1° 09:55	10.65	100%	109.7°
2042-02-05 Wed	32	—	unknown	04:25–05:55 (good, 1.5 h)	87.1° 09:55	10.62	99%	106.5°
2042-02-06 Thu	30	—	unknown	04:25–05:55 (good, 1.5 h)	87.1° 09:50	10.58	97%	102.8°
2042-02-07 Fri	30	—	unknown	04:25–05:55 (good, 1.5 h)	87.1° 09:45	10.55	93%	98.5°
2042-02-08 Sat	30	—	unknown	04:25–05:55 (good, 1.5 h)	87.1° 09:40	10.51	87%	94.0°
2042-02-09 Sun	30	—	unknown	04:15–05:50 (good, 1.58 h)	87.1° 09:35	10.47	80%	89.3°
2042-02-10 Mon	32	—	unknown	04:05–05:50 (good, 1.75 h)	87.1° 09:35	10.44	72%	84.6°
2042-02-11 Tue	35	—	unknown	04:00–05:50 (good, 1.83 h)	87.1° 09:30	10.4	63%	80.1°
2042-02-12 Wed	39	—	unknown	03:50–05:50 (good, 2.0 h)	87.1° 09:25	10.36	54%	75.9°
2042-02-13 Thu	42	—	unknown	03:40–05:45 (good, 2.08 h)	87.1° 09:20	10.32	44%	72.3°
2042-02-14 Fri	49	—	unknown	03:25–05:45 (good, 2.33 h)	87.1° 09:20	10.28	34%	69.3°
2042-02-15 Sat	54	—	unknown	03:20–05:45 (good, 2.42 h)	87.1° 09:15	10.24	24%	67.4°
2042-02-16 Sun	61	—	unknown	03:15–05:45 (good, 2.5 h)	87.1° 09:10	10.2	15%	66.6°
2042-02-17 Mon	63	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:05	10.16	8%	67.4°
2042-02-18 Tue	65	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:00	10.12	3%	69.6°
2042-02-19 Wed	66	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 09:00	10.08	0%	73.2°
2042-02-20 Thu	67	—	unknown	03:00–05:40 (good, 2.67 h)	87.1° 08:55	10.04	1%	78.0°
2042-02-21 Fri	67	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:50	9.99	4%	83.6°
2042-02-22 Sat	69	—	unknown	02:50–05:35 (good, 2.75 h)	87.1° 08:45	9.95	10%	89.4°
2042-02-23 Sun	71	—	unknown	02:50–05:35 (good, 2.75 h)	87.1° 08:40	9.91	18%	95.2°
2042-02-24 Mon	71	—	unknown	02:45–05:30 (good, 2.75 h)	87.1° 08:40	9.86	28%	100.6°
2042-02-25 Tue	72	—	unknown	02:40–05:30 (good, 2.83 h)	87.1° 08:35	9.82	39%	105.3°
2042-02-26 Wed	74	—	unknown	02:35–05:30 (good, 2.92 h)	87.1° 08:30	9.78	50%	109.0°
2042-02-27 Thu	75	—	unknown	02:40–05:30 (good, 2.83 h)	87.1° 08:25	9.73	60%	111.6°
2042-02-28 Fri	73	—	unknown	02:35–05:25 (good, 2.83 h)	87.1° 08:25	9.69	70%	113.0°
2042-03-01 Sat	71	—	unknown	02:35–05:25 (good, 2.83 h)	87.1° 08:20	9.64	79%	113.2°
2042-03-02 Sun	64	—	unknown	02:35–05:25 (good, 2.83 h)	87.1° 08:15	9.6	86%	112.3°
2042-03-03 Mon	60	—	unknown	02:35–05:20 (good, 2.75 h)	87.1° 08:10	9.55	92%	110.3°
2042-03-04 Tue	57	—	unknown	02:35–05:20 (good, 2.75 h)	87.1° 08:05	9.5	97%	107.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-02-03&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.