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: 04-03 (49), 04-04 (49), 04-01 (48), 04-02 (47), 04-05 (47) — by astronomy; check the weather when the night is within four days.

2028-03-07astronomy score per night — click a bar for that night2028-04-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-03-07 Tue	25	—	unknown	04:20–05:15 (good, 0.92 h)	71.1° 09:15	9.34	86%	137.9°
2028-03-08 Wed	24	—	unknown	04:20–05:15 (good, 0.92 h)	71.1° 09:15	9.29	93%	138.4°
2028-03-09 Thu	23	—	unknown	04:15–05:10 (good, 0.92 h)	71.1° 09:10	9.25	98%	134.6°
2028-03-10 Fri	24	—	unknown	04:15–05:10 (good, 0.92 h)	71.1° 09:05	9.2	100%	127.3°
2028-03-11 Sat	23	—	unknown	04:10–05:05 (good, 0.92 h)	71.1° 09:00	9.15	99%	118.0°
2028-03-12 Sun	21	—	unknown	04:15–05:05 (good, 0.83 h)	71.1° 08:55	9.1	95%	107.6°
2028-03-13 Mon	20	—	unknown	04:15–05:05 (good, 0.83 h)	71.1° 08:55	9.05	88%	97.0°
2028-03-14 Tue	19	—	unknown	04:10–05:00 (good, 0.83 h)	71.1° 08:50	9.0	80%	86.4°
2028-03-15 Wed	20	—	unknown	04:10–05:00 (good, 0.83 h)	71.1° 08:45	8.95	70%	76.4°
2028-03-16 Thu	21	—	unknown	04:00–05:00 (good, 1.0 h)	71.1° 08:40	8.9	60%	67.0°
2028-03-17 Fri	22	—	unknown	03:55–04:55 (good, 1.0 h)	71.1° 08:40	8.85	50%	58.5°
2028-03-18 Sat	25	—	unknown	03:45–04:55 (good, 1.17 h)	71.1° 08:35	8.8	41%	51.2°
2028-03-19 Sun	29	—	unknown	03:30–04:55 (good, 1.42 h)	71.1° 08:30	8.75	31%	45.6°
2028-03-20 Mon	34	—	unknown	03:25–04:50 (good, 1.42 h)	71.1° 08:25	8.7	23%	42.2°
2028-03-21 Tue	37	—	unknown	03:20–04:50 (good, 1.5 h)	71.1° 08:20	8.64	16%	41.3°
2028-03-22 Wed	39	—	unknown	03:15–04:50 (good, 1.58 h)	71.1° 08:20	8.59	9%	43.2°
2028-03-23 Thu	39	—	unknown	03:15–04:45 (good, 1.5 h)	71.1° 08:15	8.54	5%	47.5°
2028-03-24 Fri	40	—	unknown	03:10–04:45 (good, 1.58 h)	71.1° 08:10	8.49	2%	53.6°
2028-03-25 Sat	40	—	unknown	04:05–05:40 (good, 1.58 h)	71.1° 09:05	8.43	0%	61.0°
2028-03-26 Sun	42	—	unknown	04:00–05:40 (good, 1.67 h)	71.1° 09:00	8.38	1%	69.3°
2028-03-27 Mon	43	—	unknown	03:55–05:40 (good, 1.75 h)	71.1° 09:00	8.33	3%	78.2°
2028-03-28 Tue	44	—	unknown	03:55–05:35 (good, 1.67 h)	71.1° 08:55	8.27	7%	87.5°
2028-03-29 Wed	45	—	unknown	03:50–05:35 (good, 1.75 h)	71.1° 08:50	8.22	13%	97.0°
2028-03-30 Thu	44	—	unknown	03:45–05:30 (good, 1.75 h)	71.1° 08:45	8.16	21%	106.5°
2028-03-31 Fri	46	—	unknown	03:40–05:30 (good, 1.83 h)	71.1° 08:45	8.11	30%	115.7°
2028-04-01 Sat	48	—	unknown	03:35–05:30 (good, 1.92 h)	71.1° 08:40	8.05	40%	124.3°
2028-04-02 Sun	47	—	unknown	03:35–05:25 (good, 1.83 h)	71.1° 08:35	8.0	51%	131.7°
2028-04-03 Mon	49	—	unknown	03:35–05:25 (good, 1.83 h)	71.1° 08:30	7.94	63%	137.0°
2028-04-04 Tue	49	—	unknown	03:30–05:25 (good, 1.92 h)	71.1° 08:25	7.89	73%	138.9°
2028-04-05 Wed	47	—	unknown	03:30–05:20 (good, 1.83 h)	71.1° 08:25	7.83	83%	136.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-03-07&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.