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: 03-11 (29), 03-08 (28), 03-09 (28), 03-10 (28), 03-12 (28) — by astronomy; check the weather when the night is within four days.

2033-02-21astronomy score per night — click a bar for that night2033-03-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-02-21 Mon	10	—	unknown	05:30–05:35 (good, 0.08 h)	71.1° 10:15	9.99	56%	74.4°
2033-02-22 Tue	11	—	unknown	05:25–05:35 (good, 0.17 h)	71.1° 10:10	9.94	46%	64.8°
2033-02-23 Wed	13	—	unknown	05:20–05:35 (good, 0.25 h)	71.1° 10:05	9.9	35%	55.5°
2033-02-24 Thu	14	—	unknown	05:10–05:30 (good, 0.33 h)	71.1° 10:00	9.86	25%	47.0°
2033-02-25 Fri	17	—	unknown	05:00–05:30 (good, 0.5 h)	71.1° 09:55	9.81	16%	40.5°
2033-02-26 Sat	19	—	unknown	04:50–05:30 (good, 0.67 h)	71.1° 09:55	9.77	9%	37.3°
2033-02-27 Sun	21	—	unknown	04:50–05:30 (good, 0.67 h)	71.1° 09:50	9.72	3%	38.9°
2033-02-28 Mon	21	—	unknown	04:45–05:25 (good, 0.67 h)	71.1° 09:45	9.68	0%	44.9°
2033-03-01 Tue	22	—	unknown	04:40–05:25 (good, 0.75 h)	71.1° 09:40	9.63	1%	54.0°
2033-03-02 Wed	23	—	unknown	04:35–05:25 (good, 0.83 h)	71.1° 09:40	9.59	4%	64.8°
2033-03-03 Thu	23	—	unknown	04:30–05:20 (good, 0.83 h)	71.1° 09:35	9.54	10%	76.3°
2033-03-04 Fri	24	—	unknown	04:30–05:20 (good, 0.83 h)	71.1° 09:30	9.49	18%	87.9°
2033-03-05 Sat	25	—	unknown	04:25–05:20 (good, 0.92 h)	71.1° 09:25	9.45	28%	99.2°
2033-03-06 Sun	25	—	unknown	04:20–05:15 (good, 0.92 h)	71.1° 09:20	9.4	38%	110.0°
2033-03-07 Mon	26	—	unknown	04:15–05:15 (good, 1.0 h)	71.1° 09:20	9.35	49%	119.9°
2033-03-08 Tue	28	—	unknown	04:15–05:15 (good, 1.0 h)	71.1° 09:15	9.31	59%	128.7°
2033-03-09 Wed	28	—	unknown	04:10–05:10 (good, 1.0 h)	71.1° 09:10	9.26	69%	135.9°
2033-03-10 Thu	28	—	unknown	04:05–05:10 (good, 1.08 h)	71.1° 09:05	9.21	78%	140.9°
2033-03-11 Fri	29	—	unknown	04:05–05:10 (good, 1.08 h)	71.1° 09:00	9.16	85%	142.8°
2033-03-12 Sat	28	—	unknown	04:05–05:05 (good, 1.0 h)	71.1° 09:00	9.11	91%	141.5°
2033-03-13 Sun	26	—	unknown	04:00–05:05 (good, 1.08 h)	71.1° 08:55	9.06	96%	137.2°
2033-03-14 Mon	27	—	unknown	04:00–05:05 (good, 1.08 h)	71.1° 08:50	9.01	99%	130.9°
2033-03-15 Tue	26	—	unknown	03:55–05:00 (good, 1.08 h)	71.1° 08:45	8.96	100%	123.2°
2033-03-16 Wed	25	—	unknown	03:55–05:00 (good, 1.08 h)	71.1° 08:45	8.91	99%	114.6°
2033-03-17 Thu	22	—	unknown	03:55–04:55 (good, 1.0 h)	71.1° 08:40	8.86	97%	105.5°
2033-03-18 Fri	21	—	unknown	04:00–04:55 (good, 0.92 h)	71.1° 08:35	8.81	93%	96.1°
2033-03-19 Sat	20	—	unknown	04:10–04:55 (good, 0.75 h)	71.1° 08:30	8.76	87%	86.5°
2033-03-20 Sun	19	—	unknown	04:20–04:50 (good, 0.5 h)	71.1° 08:25	8.71	80%	76.9°
2033-03-21 Mon	19	—	unknown	04:20–04:50 (good, 0.5 h)	71.1° 08:25	8.65	71%	67.3°
2033-03-22 Tue	21	—	unknown	03:55–04:50 (good, 0.92 h)	71.1° 08:20	8.6	62%	58.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-02-21&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.