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: 03-05 (25), 03-06 (25), 03-04 (24), 03-03 (23), 03-02 (20) — by astronomy; check the weather when the night is within four days.

2046-02-05astronomy score per night — click a bar for that night2046-03-06

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-02-05 Mon	3	—	unknown	06:15–06:30 (marginal, 0.25 h)	71.1° 11:15	10.62	0%	42.5°
2046-02-06 Tue	3	—	unknown	06:10–06:25 (marginal, 0.25 h)	71.1° 11:15	10.58	1%	44.6°
2046-02-07 Wed	4	—	unknown	05:40–05:55 (marginal, 0.25 h)	71.1° 11:10	10.54	4%	48.9°
2046-02-08 Thu	5	—	unknown	05:35–05:55 (marginal, 0.33 h)	71.1° 11:05	10.51	8%	55.0°
2046-02-09 Fri	5	—	unknown	06:00–06:25 (marginal, 0.42 h)	71.1° 11:00	10.47	14%	62.2°
2046-02-10 Sat	6	—	unknown	05:55–06:25 (marginal, 0.5 h)	71.1° 10:55	10.43	21%	70.2°
2046-02-11 Sun	6	—	unknown	05:25–06:20 (marginal, 0.92 h)	71.1° 10:55	10.4	29%	78.8°
2046-02-12 Mon	8	—	unknown	05:20–06:20 (marginal, 1.0 h)	71.1° 10:50	10.36	38%	87.8°
2046-02-13 Tue	8	—	unknown	05:15–06:20 (marginal, 1.08 h)	71.1° 10:45	10.32	48%	97.0°
2046-02-14 Wed	8	—	unknown	05:40–05:45 (good, 0.08 h)	71.1° 10:40	10.28	58%	106.2°
2046-02-15 Thu	9	—	unknown	05:35–05:45 (good, 0.17 h)	71.1° 10:40	10.24	68%	115.4°
2046-02-16 Fri	11	—	unknown	05:30–05:45 (good, 0.25 h)	71.1° 10:35	10.2	78%	124.0°
2046-02-17 Sat	11	—	unknown	05:30–05:40 (good, 0.17 h)	71.1° 10:30	10.16	87%	131.3°
2046-02-18 Sun	11	—	unknown	05:30–05:40 (good, 0.17 h)	71.1° 10:25	10.12	94%	136.3°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-02-05&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.