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: 04-22 (65), 04-24 (65), 04-20 (64), 04-21 (64), 04-23 (64) — by astronomy; check the weather when the night is within four days.

2029-03-26astronomy score per night — click a bar for that night2029-04-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-03-26 Mon	39	—	unknown	04:10–05:40 (good, 1.5 h)	71.1° 09:05	8.39	86%	139.4°
2029-03-27 Tue	36	—	unknown	04:05–05:40 (good, 1.58 h)	71.1° 09:00	8.34	93%	134.6°
2029-03-28 Wed	36	—	unknown	04:05–05:35 (good, 1.5 h)	71.1° 08:55	8.28	98%	126.5°
2029-03-29 Thu	34	—	unknown	04:05–05:35 (good, 1.5 h)	71.1° 08:50	8.23	100%	116.5°
2029-03-30 Fri	31	—	unknown	04:05–05:35 (good, 1.5 h)	71.1° 08:45	8.18	99%	105.3°
2029-03-31 Sat	27	—	unknown	04:10–05:30 (good, 1.33 h)	71.1° 08:45	8.12	95%	93.7°
2029-04-01 Sun	26	—	unknown	04:20–05:30 (good, 1.17 h)	71.1° 08:40	8.07	88%	82.3°
2029-04-02 Mon	25	—	unknown	04:25–05:25 (good, 1.0 h)	71.1° 08:35	8.01	80%	71.3°
2029-04-03 Tue	26	—	unknown	04:10–05:25 (good, 1.25 h)	71.1° 08:30	7.96	70%	61.3°
2029-04-04 Wed	28	—	unknown	03:50–05:25 (good, 1.58 h)	71.1° 08:30	7.9	59%	52.5°
2029-04-05 Thu	31	—	unknown	03:40–05:20 (good, 1.67 h)	71.1° 08:25	7.85	49%	45.5°
2029-04-06 Fri	38	—	unknown	03:20–05:20 (good, 2.0 h)	71.1° 08:20	7.79	39%	41.0°
2029-04-07 Sat	44	—	unknown	03:15–05:15 (good, 2.0 h)	71.1° 08:15	7.73	29%	39.5°
2029-04-08 Sun	48	—	unknown	03:10–05:15 (good, 2.08 h)	71.1° 08:10	7.68	21%	41.2°
2029-04-09 Mon	53	—	unknown	03:05–05:15 (good, 2.17 h)	71.1° 08:10	7.62	14%	45.5°
2029-04-10 Tue	54	—	unknown	03:05–05:10 (good, 2.08 h)	71.1° 08:05	7.56	8%	51.7°
2029-04-11 Wed	56	—	unknown	03:00–05:10 (good, 2.17 h)	71.1° 08:00	7.51	4%	59.2°
2029-04-12 Thu	56	—	unknown	02:55–05:05 (good, 2.17 h)	71.1° 07:55	7.45	1%	67.5°
2029-04-13 Fri	57	—	unknown	02:50–05:05 (good, 2.25 h)	71.1° 07:50	7.39	0%	76.3°
2029-04-14 Sat	59	—	unknown	02:45–05:05 (good, 2.33 h)	71.1° 07:50	7.33	1%	85.4°
2029-04-15 Sun	59	—	unknown	02:45–05:00 (good, 2.25 h)	71.1° 07:45	7.28	4%	94.6°
2029-04-16 Mon	60	—	unknown	02:40–05:00 (good, 2.33 h)	71.1° 07:40	7.22	8%	103.8°
2029-04-17 Tue	61	—	unknown	02:35–05:00 (good, 2.42 h)	71.1° 07:35	7.16	14%	112.8°
2029-04-18 Wed	62	—	unknown	02:30–04:55 (good, 2.42 h)	71.1° 07:35	7.1	22%	121.4°
2029-04-19 Thu	63	—	unknown	02:30–04:55 (good, 2.42 h)	71.1° 07:30	7.05	31%	129.3°
2029-04-20 Fri	64	—	unknown	02:25–04:50 (good, 2.42 h)	71.1° 07:25	6.99	40%	135.7°
2029-04-21 Sat	64	—	unknown	02:25–04:50 (good, 2.42 h)	71.1° 07:20	6.93	51%	139.8°
2029-04-22 Sun	65	—	unknown	02:20–04:50 (good, 2.5 h)	71.1° 07:15	6.87	62%	140.4°
2029-04-23 Mon	64	—	unknown	02:20–04:45 (good, 2.42 h)	71.1° 07:15	6.81	73%	137.1°
2029-04-24 Tue	65	—	unknown	02:15–04:45 (good, 2.5 h)	71.1° 07:10	6.75	82%	130.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-03-26&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.