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: 02-28 (68), 02-27 (62), 02-14 (59), 02-12 (58), 02-13 (58) — by astronomy; check the weather when the night is within four days.

2038-01-30astronomy score per night — click a bar for that night2038-02-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-01-30 Sat	37	—	unknown	04:20–06:00 (good, 1.67 h)	87.1° 10:15	10.82	19%	62.2°
2038-01-31 Sun	41	—	unknown	04:20–06:00 (good, 1.67 h)	87.1° 10:15	10.79	11%	60.9°
2038-02-01 Mon	43	—	unknown	04:15–06:00 (good, 1.75 h)	87.1° 10:10	10.75	6%	61.4°
2038-02-02 Tue	45	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:05	10.72	2%	63.4°
2038-02-03 Wed	47	—	unknown	04:05–06:00 (good, 1.92 h)	87.1° 10:00	10.69	0%	66.8°
2038-02-04 Thu	47	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 09:55	10.65	0%	71.2°
2038-02-05 Fri	49	—	unknown	04:00–05:55 (good, 1.92 h)	87.1° 09:55	10.62	3%	76.3°
2038-02-06 Sat	49	—	unknown	03:55–05:55 (good, 2.0 h)	87.1° 09:50	10.58	7%	81.8°
2038-02-07 Sun	51	—	unknown	03:50–05:55 (good, 2.08 h)	87.1° 09:45	10.55	13%	87.5°
2038-02-08 Mon	53	—	unknown	03:45–05:55 (good, 2.17 h)	87.1° 09:40	10.51	20%	93.3°
2038-02-09 Tue	53	—	unknown	03:45–05:50 (good, 2.08 h)	87.1° 09:35	10.47	28%	98.9°
2038-02-10 Wed	55	—	unknown	03:40–05:50 (good, 2.17 h)	87.1° 09:35	10.44	36%	104.2°
2038-02-11 Thu	56	—	unknown	03:35–05:50 (good, 2.25 h)	87.1° 09:30	10.4	46%	109.1°
2038-02-12 Fri	58	—	unknown	03:30–05:50 (good, 2.33 h)	87.1° 09:25	10.36	55%	113.2°
2038-02-13 Sat	58	—	unknown	03:25–05:45 (good, 2.33 h)	87.1° 09:20	10.32	65%	116.5°
2038-02-14 Sun	59	—	unknown	03:30–05:45 (good, 2.25 h)	87.1° 09:20	10.28	74%	118.5°
2038-02-15 Mon	58	—	unknown	03:30–05:45 (good, 2.25 h)	87.1° 09:15	10.24	83%	119.0°
2038-02-16 Tue	57	—	unknown	03:25–05:45 (good, 2.33 h)	87.1° 09:10	10.2	90%	117.8°
2038-02-17 Wed	49	—	unknown	03:25–05:40 (good, 2.25 h)	87.1° 09:05	10.16	96%	114.8°
2038-02-18 Thu	46	—	unknown	03:30–05:40 (good, 2.17 h)	87.1° 09:00	10.12	99%	110.2°
2038-02-19 Fri	42	—	unknown	03:30–05:40 (good, 2.17 h)	87.1° 09:00	10.08	100%	104.4°
2038-02-20 Sat	38	—	unknown	03:50–05:40 (good, 1.83 h)	87.1° 08:55	10.04	98%	97.6°
2038-02-21 Sun	35	—	unknown	04:10–05:35 (good, 1.42 h)	87.1° 08:50	10.0	92%	90.5°
2038-02-22 Mon	35	—	unknown	04:15–05:35 (good, 1.33 h)	87.1° 08:45	9.95	85%	83.3°
2038-02-23 Tue	36	—	unknown	03:55–05:35 (good, 1.67 h)	87.1° 08:40	9.91	76%	76.6°
2038-02-24 Wed	40	—	unknown	03:15–05:30 (good, 2.25 h)	87.1° 08:40	9.87	65%	70.8°
2038-02-25 Thu	45	—	unknown	03:00–05:30 (good, 2.5 h)	87.1° 08:35	9.82	54%	66.1°
2038-02-26 Fri	53	—	unknown	02:50–05:30 (good, 2.67 h)	87.1° 08:30	9.78	43%	62.8°
2038-02-27 Sat	62	—	unknown	02:30–05:30 (good, 3.0 h)	87.1° 08:25	9.73	32%	61.2°
2038-02-28 Sun	68	—	unknown	02:30–05:25 (good, 2.92 h)	87.1° 08:25	9.69	23%	61.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-01-30&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.