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 (91), 03-13 (91), 03-11 (89), 03-10 (86), 03-09 (79) — by astronomy; check the weather when the night is within four days.

2048-02-13astronomy score per night — click a bar for that night2048-03-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2048-02-13 Thu	59	—	unknown	03:30–05:50 (good, 2.33 h)	87.1° 09:25	10.34	0%	64.6°
2048-02-14 Fri	58	—	unknown	03:25–05:45 (good, 2.33 h)	87.1° 09:20	10.3	1%	68.9°
2048-02-15 Sat	60	—	unknown	03:20–05:45 (good, 2.42 h)	87.1° 09:15	10.26	4%	74.2°
2048-02-16 Sun	62	—	unknown	03:15–05:45 (good, 2.5 h)	87.1° 09:10	10.22	10%	80.0°
2048-02-17 Mon	63	—	unknown	03:15–05:45 (good, 2.5 h)	87.1° 09:10	10.18	16%	86.0°
2048-02-18 Tue	63	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:05	10.14	24%	92.1°
2048-02-19 Wed	64	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 09:00	10.1	33%	98.0°
2048-02-20 Thu	66	—	unknown	03:00–05:40 (good, 2.67 h)	87.1° 08:55	10.05	42%	103.5°
2048-02-21 Fri	67	—	unknown	03:00–05:35 (good, 2.58 h)	87.1° 08:50	10.01	51%	108.5°
2048-02-22 Sat	69	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:50	9.97	61%	112.9°
2048-02-23 Sun	68	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:45	9.93	70%	116.3°
2048-02-24 Mon	69	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:40	9.88	78%	118.6°
2048-02-25 Tue	68	—	unknown	02:50–05:30 (good, 2.67 h)	87.1° 08:35	9.84	86%	119.6°
2048-02-26 Wed	67	—	unknown	02:50–05:30 (good, 2.67 h)	87.1° 08:30	9.8	92%	119.0°
2048-02-27 Thu	60	—	unknown	02:50–05:30 (good, 2.67 h)	87.1° 08:30	9.75	97%	116.8°
2048-02-28 Fri	56	—	unknown	02:50–05:25 (good, 2.58 h)	87.1° 08:25	9.71	99%	113.1°
2048-02-29 Sat	53	—	unknown	02:50–05:25 (good, 2.58 h)	87.1° 08:20	9.66	100%	108.0°
2048-03-01 Sun	50	—	unknown	02:50–05:25 (good, 2.58 h)	87.1° 08:15	9.62	98%	102.0°
2048-03-02 Mon	47	—	unknown	02:50–05:20 (good, 2.5 h)	87.1° 08:15	9.57	93%	95.3°
2048-03-03 Tue	46	—	unknown	02:50–05:20 (good, 2.5 h)	87.1° 08:10	9.52	86%	88.3°
2048-03-04 Wed	47	—	unknown	02:40–05:20 (good, 2.67 h)	87.1° 08:05	9.48	77%	81.4°
2048-03-05 Thu	49	—	unknown	02:30–05:15 (good, 2.75 h)	87.1° 08:00	9.43	67%	74.8°
2048-03-06 Fri	55	—	unknown	02:20–05:15 (good, 2.92 h)	87.1° 07:55	9.38	56%	69.1°
2048-03-07 Sat	63	—	unknown	02:00–05:15 (good, 3.25 h)	87.1° 07:55	9.34	44%	64.6°
2048-03-08 Sun	70	—	unknown	01:55–05:10 (good, 3.25 h)	87.1° 07:50	9.29	34%	61.6°
2048-03-09 Mon	79	—	unknown	01:50–05:10 (good, 3.33 h)	87.1° 07:45	9.24	23%	60.4°
2048-03-10 Tue	86	—	unknown	01:45–05:10 (good, 3.42 h)	87.1° 07:40	9.19	15%	61.0°
2048-03-11 Wed	89	—	unknown	01:45–05:05 (good, 3.33 h)	87.1° 07:35	9.14	8%	63.5°
2048-03-12 Thu	91	—	unknown	01:40–05:05 (good, 3.42 h)	87.1° 07:35	9.09	3%	67.3°
2048-03-13 Fri	91	—	unknown	01:35–05:05 (good, 3.5 h)	87.1° 07:30	9.04	1%	72.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-02-13&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.