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: 02-26 (74), 02-25 (72), 02-23 (71), 02-24 (71), 02-22 (69) — by astronomy; check the weather when the night is within four days.

2039-01-28astronomy score per night — click a bar for that night2039-02-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-01-28 Fri	39	—	unknown	04:30–06:05 (good, 1.58 h)	87.1° 10:25	10.89	20%	88.6°
2039-01-29 Sat	40	—	unknown	04:25–06:00 (good, 1.58 h)	87.1° 10:20	10.86	29%	94.3°
2039-01-30 Sun	41	—	unknown	04:25–06:00 (good, 1.58 h)	87.1° 10:20	10.83	38%	99.7°
2039-01-31 Mon	42	—	unknown	04:20–06:00 (good, 1.67 h)	87.1° 10:15	10.79	48%	104.6°
2039-02-01 Tue	43	—	unknown	04:15–06:00 (good, 1.75 h)	87.1° 10:10	10.76	57%	109.0°
2039-02-02 Wed	45	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:05	10.73	66%	112.7°
2039-02-03 Thu	47	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:00	10.7	75%	115.4°
2039-02-04 Fri	46	—	unknown	04:10–05:55 (good, 1.75 h)	87.1° 10:00	10.66	83%	117.0°
2039-02-05 Sat	45	—	unknown	04:10–05:55 (good, 1.75 h)	87.1° 09:55	10.63	89%	117.3°
2039-02-06 Sun	40	—	unknown	04:10–05:55 (good, 1.75 h)	87.1° 09:50	10.59	95%	116.2°
2039-02-07 Mon	38	—	unknown	04:10–05:55 (good, 1.75 h)	87.1° 09:45	10.56	98%	113.8°
2039-02-08 Tue	37	—	unknown	04:10–05:55 (good, 1.75 h)	87.1° 09:40	10.52	100%	110.0°
2039-02-09 Wed	34	—	unknown	04:10–05:50 (good, 1.67 h)	87.1° 09:40	10.48	99%	105.2°
2039-02-10 Thu	32	—	unknown	04:15–05:50 (good, 1.58 h)	87.1° 09:35	10.45	96%	99.6°
2039-02-11 Fri	30	—	unknown	04:30–05:50 (good, 1.33 h)	87.1° 09:30	10.41	91%	93.4°
2039-02-12 Sat	30	—	unknown	04:35–05:50 (good, 1.25 h)	87.1° 09:25	10.37	83%	87.0°
2039-02-13 Sun	31	—	unknown	04:15–05:45 (good, 1.5 h)	87.1° 09:25	10.33	74%	80.7°
2039-02-14 Mon	34	—	unknown	03:50–05:45 (good, 1.92 h)	87.1° 09:20	10.29	63%	74.8°
2039-02-15 Tue	39	—	unknown	03:40–05:45 (good, 2.08 h)	87.1° 09:15	10.25	52%	69.8°
2039-02-16 Wed	45	—	unknown	03:30–05:45 (good, 2.25 h)	87.1° 09:10	10.21	41%	65.9°
2039-02-17 Thu	52	—	unknown	03:15–05:40 (good, 2.42 h)	87.1° 09:05	10.17	30%	63.4°
2039-02-18 Fri	59	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:05	10.13	20%	62.7°
2039-02-19 Sat	65	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 09:00	10.09	12%	63.7°
2039-02-20 Sun	67	—	unknown	03:00–05:40 (good, 2.67 h)	87.1° 08:55	10.05	6%	66.4°
2039-02-21 Mon	67	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:50	10.01	2%	70.3°
2039-02-22 Tue	69	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:45	9.96	0%	75.1°
2039-02-23 Wed	71	—	unknown	02:50–05:35 (good, 2.75 h)	87.1° 08:45	9.92	1%	80.6°
2039-02-24 Thu	71	—	unknown	02:45–05:35 (good, 2.83 h)	87.1° 08:40	9.88	4%	86.3°
2039-02-25 Fri	72	—	unknown	02:40–05:30 (good, 2.83 h)	87.1° 08:35	9.83	8%	92.0°
2039-02-26 Sat	74	—	unknown	02:35–05:30 (good, 2.92 h)	87.1° 08:30	9.79	14%	97.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-01-28&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.