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: 03-17 (34), 03-14 (33), 03-16 (33), 03-15 (32), 03-13 (31) — by astronomy; check the weather when the night is within four days.

2029-02-16astronomy score per night — click a bar for that night2029-03-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-02-16 Fri	11	—	unknown	05:30–05:45 (good, 0.25 h)	71.1° 10:35	10.19	11%	63.5°
2029-02-17 Sat	11	—	unknown	05:25–05:40 (good, 0.25 h)	71.1° 10:30	10.15	18%	72.0°
2029-02-18 Sun	13	—	unknown	05:25–05:40 (good, 0.25 h)	71.1° 10:25	10.11	25%	80.9°
2029-02-19 Mon	14	—	unknown	05:20–05:40 (good, 0.33 h)	71.1° 10:20	10.07	34%	90.0°
2029-02-20 Tue	15	—	unknown	05:15–05:40 (good, 0.42 h)	71.1° 10:15	10.03	43%	99.2°
2029-02-21 Wed	15	—	unknown	05:10–05:35 (good, 0.42 h)	71.1° 10:15	9.99	53%	108.4°
2029-02-22 Thu	16	—	unknown	05:10–05:35 (good, 0.42 h)	71.1° 10:10	9.94	63%	117.4°
2029-02-23 Fri	18	—	unknown	05:05–05:35 (good, 0.5 h)	71.1° 10:05	9.9	73%	126.0°
2029-02-24 Sat	17	—	unknown	05:00–05:30 (good, 0.5 h)	71.1° 10:00	9.86	82%	133.4°
2029-02-25 Sun	18	—	unknown	05:05–05:30 (good, 0.42 h)	71.1° 09:55	9.81	89%	138.6°
2029-02-26 Mon	17	—	unknown	05:00–05:30 (good, 0.5 h)	71.1° 09:55	9.77	95%	140.2°
2029-02-27 Tue	17	—	unknown	04:55–05:30 (good, 0.58 h)	71.1° 09:50	9.72	99%	137.6°
2029-02-28 Wed	17	—	unknown	04:55–05:25 (good, 0.5 h)	71.1° 09:45	9.68	100%	131.1°
2029-03-01 Thu	17	—	unknown	04:50–05:25 (good, 0.58 h)	71.1° 09:40	9.63	98%	122.0°
2029-03-02 Fri	17	—	unknown	04:50–05:25 (good, 0.58 h)	71.1° 09:40	9.59	92%	111.5°
2029-03-03 Sat	16	—	unknown	04:50–05:20 (good, 0.5 h)	71.1° 09:35	9.54	85%	100.4°
2029-03-04 Sun	15	—	unknown	04:50–05:20 (good, 0.5 h)	71.1° 09:30	9.5	76%	89.2°
2029-03-05 Mon	16	—	unknown	04:45–05:20 (good, 0.58 h)	71.1° 09:25	9.45	65%	78.4°
2029-03-06 Tue	16	—	unknown	04:40–05:15 (good, 0.58 h)	71.1° 09:20	9.4	54%	68.1°
2029-03-07 Wed	18	—	unknown	04:30–05:15 (good, 0.75 h)	71.1° 09:20	9.35	44%	58.7°
2029-03-08 Thu	21	—	unknown	04:25–05:15 (good, 0.83 h)	71.1° 09:15	9.31	33%	50.6°
2029-03-09 Fri	24	—	unknown	04:10–05:10 (good, 1.0 h)	71.1° 09:10	9.26	24%	44.4°
2029-03-10 Sat	27	—	unknown	04:05–05:10 (good, 1.08 h)	71.1° 09:05	9.21	16%	40.6°
2029-03-11 Sun	30	—	unknown	04:00–05:10 (good, 1.17 h)	71.1° 09:00	9.16	10%	39.8°
2029-03-12 Mon	30	—	unknown	03:55–05:05 (good, 1.17 h)	71.1° 09:00	9.11	5%	42.2°
2029-03-13 Tue	31	—	unknown	03:55–05:05 (good, 1.17 h)	71.1° 08:55	9.06	2%	47.0°
2029-03-14 Wed	33	—	unknown	03:50–05:05 (good, 1.25 h)	71.1° 08:50	9.01	0%	53.6°
2029-03-15 Thu	32	—	unknown	03:45–05:00 (good, 1.25 h)	71.1° 08:45	8.96	1%	61.3°
2029-03-16 Fri	33	—	unknown	03:40–05:00 (good, 1.33 h)	71.1° 08:45	8.91	3%	69.7°
2029-03-17 Sat	34	—	unknown	03:35–04:55 (good, 1.33 h)	71.1° 08:40	8.86	7%	78.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-02-16&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.