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: 03-14 (32), 03-13 (31), 03-15 (31), 03-11 (30), 03-12 (30) — by astronomy; check the weather when the night is within four days.

2030-02-14astronomy score per night — click a bar for that night2030-03-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-02-14 Thu	8	—	unknown	05:40–05:45 (good, 0.08 h)	71.1° 10:40	10.28	88%	134.7°
2030-02-15 Fri	8	—	unknown	05:10–06:15 (marginal, 1.08 h)	71.1° 10:40	10.24	94%	139.7°
2030-02-16 Sat	9	—	unknown	05:40–05:45 (good, 0.08 h)	71.1° 10:35	10.2	98%	141.5°
2030-02-17 Sun	9	—	unknown	05:35–05:40 (good, 0.08 h)	71.1° 10:30	10.16	100%	139.5°
2030-02-18 Mon	10	—	unknown	05:35–05:40 (good, 0.08 h)	71.1° 10:25	10.12	99%	134.0°
2030-02-19 Tue	10	—	unknown	05:30–05:40 (good, 0.17 h)	71.1° 10:20	10.08	96%	125.9°
2030-02-20 Wed	11	—	unknown	05:30–05:40 (good, 0.17 h)	71.1° 10:20	10.04	91%	116.1°
2030-02-21 Thu	10	—	unknown	05:30–05:35 (good, 0.08 h)	71.1° 10:15	10.0	83%	105.5°
2030-02-22 Fri	11	—	unknown	05:25–05:35 (good, 0.17 h)	71.1° 10:10	9.95	74%	94.4°
2030-02-23 Sat	11	—	unknown	05:25–05:35 (good, 0.17 h)	71.1° 10:05	9.91	63%	83.3°
2030-02-24 Sun	12	—	unknown	05:20–05:30 (good, 0.17 h)	71.1° 10:00	9.87	52%	72.3°
2030-02-25 Mon	13	—	unknown	05:10–05:30 (good, 0.33 h)	71.1° 10:00	9.82	40%	62.0°
2030-02-26 Tue	15	—	unknown	05:05–05:30 (good, 0.42 h)	71.1° 09:55	9.78	30%	52.7°
2030-02-27 Wed	18	—	unknown	04:55–05:30 (good, 0.58 h)	71.1° 09:50	9.74	20%	45.0°
2030-02-28 Thu	19	—	unknown	04:45–05:25 (good, 0.67 h)	71.1° 09:45	9.69	12%	40.0°
2030-03-01 Fri	21	—	unknown	04:40–05:25 (good, 0.75 h)	71.1° 09:40	9.65	6%	38.5°
2030-03-02 Sat	23	—	unknown	04:35–05:25 (good, 0.83 h)	71.1° 09:40	9.6	2%	40.8°
2030-03-03 Sun	23	—	unknown	04:35–05:20 (good, 0.75 h)	71.1° 09:35	9.55	0%	46.2°
2030-03-04 Mon	24	—	unknown	04:30–05:20 (good, 0.83 h)	71.1° 09:30	9.51	1%	53.5°
2030-03-05 Tue	25	—	unknown	04:25–05:20 (good, 0.92 h)	71.1° 09:25	9.46	3%	62.0°
2030-03-06 Wed	25	—	unknown	04:20–05:15 (good, 0.92 h)	71.1° 09:25	9.41	7%	71.1°
2030-03-07 Thu	26	—	unknown	04:20–05:15 (good, 0.92 h)	71.1° 09:20	9.37	13%	80.3°
2030-03-08 Fri	28	—	unknown	04:15–05:15 (good, 1.0 h)	71.1° 09:15	9.32	20%	89.7°
2030-03-09 Sat	27	—	unknown	04:10–05:10 (good, 1.0 h)	71.1° 09:10	9.27	28%	99.0°
2030-03-10 Sun	29	—	unknown	04:05–05:10 (good, 1.08 h)	71.1° 09:05	9.22	37%	108.1°
2030-03-11 Mon	30	—	unknown	04:00–05:10 (good, 1.17 h)	71.1° 09:05	9.17	46%	116.8°
2030-03-12 Tue	30	—	unknown	04:00–05:05 (good, 1.08 h)	71.1° 09:00	9.12	56%	125.1°
2030-03-13 Wed	31	—	unknown	03:55–05:05 (good, 1.17 h)	71.1° 08:55	9.07	65%	132.4°
2030-03-14 Thu	32	—	unknown	03:50–05:05 (good, 1.25 h)	71.1° 08:50	9.02	74%	138.2°
2030-03-15 Fri	31	—	unknown	03:50–05:00 (good, 1.17 h)	71.1° 08:45	8.97	83%	141.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-02-14&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.