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 HD 189733: 03-22 (38), 03-19 (37), 03-20 (37), 03-21 (37), 03-18 (36) — by astronomy; check the weather when the night is within four days.

2048-02-22astronomy score per night — click a bar for that night2048-03-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2048-02-22 Sat	15	—	unknown	05:10–05:35 (good, 0.42 h)	71.1° 10:10	9.97	61%	115.6°
2048-02-23 Sun	16	—	unknown	05:05–05:35 (good, 0.5 h)	71.2° 10:10	9.93	70%	123.7°
2048-02-24 Mon	18	—	unknown	05:05–05:35 (good, 0.5 h)	71.2° 10:05	9.88	78%	131.0°
2048-02-25 Tue	18	—	unknown	05:00–05:30 (good, 0.5 h)	71.2° 10:00	9.84	86%	136.9°
2048-02-26 Wed	18	—	unknown	05:00–05:30 (good, 0.5 h)	71.2° 09:55	9.8	92%	140.3°
2048-02-27 Thu	17	—	unknown	05:00–05:30 (good, 0.5 h)	71.1° 09:55	9.75	97%	140.4°
2048-02-28 Fri	17	—	unknown	04:55–05:25 (good, 0.5 h)	71.2° 09:50	9.71	99%	137.0°
2048-02-29 Sat	17	—	unknown	04:55–05:25 (good, 0.5 h)	71.2° 09:45	9.66	100%	130.5°
2048-03-01 Sun	18	—	unknown	04:50–05:25 (good, 0.58 h)	71.2° 09:40	9.62	98%	121.9°
2048-03-02 Mon	16	—	unknown	04:50–05:20 (good, 0.5 h)	71.1° 09:35	9.57	93%	112.0°
2048-03-03 Tue	16	—	unknown	04:50–05:20 (good, 0.5 h)	71.1° 09:35	9.52	86%	101.3°
2048-03-04 Wed	15	—	unknown	04:50–05:20 (good, 0.5 h)	71.2° 09:30	9.48	77%	90.3°
2048-03-05 Thu	15	—	unknown	04:45–05:15 (good, 0.5 h)	71.2° 09:25	9.43	67%	79.3°
2048-03-06 Fri	17	—	unknown	04:40–05:15 (good, 0.58 h)	71.2° 09:20	9.38	56%	68.6°
2048-03-07 Sat	18	—	unknown	04:30–05:15 (good, 0.75 h)	71.1° 09:15	9.34	44%	58.7°
2048-03-08 Sun	20	—	unknown	04:25–05:10 (good, 0.75 h)	71.2° 09:15	9.29	34%	49.9°
2048-03-09 Mon	24	—	unknown	04:15–05:10 (good, 0.92 h)	71.2° 09:10	9.24	23%	43.2°
2048-03-10 Tue	28	—	unknown	04:05–05:10 (good, 1.08 h)	71.2° 09:05	9.19	15%	39.6°
2048-03-11 Wed	29	—	unknown	04:00–05:05 (good, 1.08 h)	71.2° 09:00	9.14	8%	39.7°
2048-03-12 Thu	30	—	unknown	03:55–05:05 (good, 1.17 h)	71.1° 08:55	9.09	3%	43.5°
2048-03-13 Fri	31	—	unknown	03:50–05:05 (good, 1.25 h)	71.2° 08:55	9.04	1%	49.9°
2048-03-14 Sat	32	—	unknown	03:50–05:00 (good, 1.17 h)	71.2° 08:50	8.99	0%	58.0°
2048-03-15 Sun	33	—	unknown	03:45–05:00 (good, 1.25 h)	71.2° 08:45	8.94	2%	66.8°
2048-03-16 Mon	34	—	unknown	03:40–05:00 (good, 1.33 h)	71.2° 08:40	8.89	6%	76.1°
2048-03-17 Tue	34	—	unknown	03:35–04:55 (good, 1.33 h)	71.1° 08:40	8.84	11%	85.5°
2048-03-18 Wed	36	—	unknown	03:35–04:55 (good, 1.33 h)	71.2° 08:35	8.79	18%	94.8°
2048-03-19 Thu	37	—	unknown	03:30–04:55 (good, 1.42 h)	71.2° 08:30	8.74	25%	104.0°
2048-03-20 Fri	37	—	unknown	03:25–04:50 (good, 1.42 h)	71.2° 08:25	8.69	34%	112.8°
2048-03-21 Sat	37	—	unknown	03:20–04:50 (good, 1.5 h)	71.1° 08:20	8.64	43%	121.2°
2048-03-22 Sun	38	—	unknown	03:15–04:45 (good, 1.5 h)	71.1° 08:20	8.58	52%	128.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-02-22&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.