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: 03-18 (34), 03-16 (33), 03-17 (33), 03-14 (32), 03-15 (32) — by astronomy; check the weather when the night is within four days.

2046-02-19astronomy score per night — click a bar for that night2046-03-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-02-19 Mon	11	—	unknown	05:30–05:40 (good, 0.17 h)	71.1° 10:20	10.08	98%	137.5°
2046-02-20 Tue	11	—	unknown	05:25–05:40 (good, 0.25 h)	71.1° 10:20	10.03	100%	134.5°
2046-02-21 Wed	12	—	unknown	05:25–05:35 (good, 0.17 h)	71.1° 10:15	9.99	98%	128.0°
2046-02-22 Thu	13	—	unknown	05:20–05:35 (good, 0.25 h)	71.1° 10:10	9.95	94%	119.1°
2046-02-23 Fri	12	—	unknown	05:20–05:35 (good, 0.25 h)	71.1° 10:05	9.91	87%	109.1°
2046-02-24 Sat	12	—	unknown	05:20–05:30 (good, 0.17 h)	71.1° 10:00	9.86	78%	98.7°
2046-02-25 Sun	12	—	unknown	05:15–05:30 (good, 0.25 h)	71.1° 10:00	9.82	68%	88.4°
2046-02-26 Mon	13	—	unknown	05:10–05:30 (good, 0.33 h)	71.1° 09:55	9.77	58%	78.4°
2046-02-27 Tue	15	—	unknown	05:05–05:30 (good, 0.42 h)	71.1° 09:50	9.73	47%	69.0°
2046-02-28 Wed	15	—	unknown	04:55–05:25 (good, 0.5 h)	71.1° 09:45	9.69	37%	60.5°
2046-03-01 Thu	17	—	unknown	04:50–05:25 (good, 0.58 h)	71.1° 09:45	9.64	28%	53.2°
2046-03-02 Fri	20	—	unknown	04:35–05:25 (good, 0.83 h)	71.1° 09:40	9.59	20%	47.4°
2046-03-03 Sat	23	—	unknown	04:35–05:20 (good, 0.75 h)	71.1° 09:35	9.55	12%	43.6°
2046-03-04 Sun	24	—	unknown	04:30–05:20 (good, 0.83 h)	71.1° 09:30	9.5	7%	42.4°
2046-03-05 Mon	25	—	unknown	04:25–05:20 (good, 0.92 h)	71.1° 09:25	9.45	3%	43.8°
2046-03-06 Tue	25	—	unknown	04:20–05:15 (good, 0.92 h)	71.1° 09:25	9.41	1%	47.7°
2046-03-07 Wed	26	—	unknown	04:20–05:15 (good, 0.92 h)	71.1° 09:20	9.36	0%	53.3°
2046-03-08 Thu	28	—	unknown	04:15–05:15 (good, 1.0 h)	71.1° 09:15	9.31	1%	60.3°
2046-03-09 Fri	27	—	unknown	04:10–05:10 (good, 1.0 h)	71.1° 09:10	9.26	4%	68.2°
2046-03-10 Sat	28	—	unknown	04:05–05:10 (good, 1.08 h)	71.1° 09:05	9.22	9%	76.7°
2046-03-11 Sun	30	—	unknown	04:00–05:10 (good, 1.17 h)	71.1° 09:05	9.17	15%	85.5°
2046-03-12 Mon	30	—	unknown	04:00–05:05 (good, 1.08 h)	71.1° 09:00	9.12	23%	94.6°
2046-03-13 Tue	31	—	unknown	03:55–05:05 (good, 1.17 h)	71.1° 08:55	9.07	32%	103.7°
2046-03-14 Wed	32	—	unknown	03:50–05:05 (good, 1.25 h)	71.1° 08:50	9.02	42%	112.7°
2046-03-15 Thu	32	—	unknown	03:45–05:00 (good, 1.25 h)	71.1° 08:50	8.97	52%	121.3°
2046-03-16 Fri	33	—	unknown	03:40–05:00 (good, 1.33 h)	71.1° 08:45	8.92	63%	128.9°
2046-03-17 Sat	33	—	unknown	03:45–04:55 (good, 1.17 h)	71.1° 08:40	8.87	74%	134.7°
2046-03-18 Sun	34	—	unknown	03:40–04:55 (good, 1.25 h)	71.1° 08:35	8.82	83%	137.6°
2046-03-19 Mon	30	—	unknown	03:40–04:55 (good, 1.25 h)	71.1° 08:30	8.77	91%	136.5°
2046-03-20 Tue	30	—	unknown	03:35–04:50 (good, 1.25 h)	71.1° 08:30	8.71	97%	131.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-02-19&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.