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: 03-26 (42), 03-24 (40), 03-25 (40), 03-23 (39), 03-22 (35) — by astronomy; check the weather when the night is within four days.

2036-02-26astronomy score per night — click a bar for that night2036-03-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-02-26 Tue	19	—	unknown	04:55–05:30 (good, 0.58 h)	71.1° 09:55	9.8	0%	49.0°
2036-02-27 Wed	20	—	unknown	04:50–05:30 (good, 0.67 h)	71.1° 09:50	9.76	0%	56.1°
2036-02-28 Thu	20	—	unknown	04:45–05:25 (good, 0.67 h)	71.1° 09:50	9.71	3%	64.3°
2036-02-29 Fri	22	—	unknown	04:45–05:25 (good, 0.67 h)	71.1° 09:45	9.67	7%	73.4°
2036-03-01 Sat	22	—	unknown	04:40–05:25 (good, 0.75 h)	71.1° 09:40	9.62	14%	83.0°
2036-03-02 Sun	22	—	unknown	04:35–05:20 (good, 0.75 h)	71.1° 09:35	9.57	22%	93.0°
2036-03-03 Mon	24	—	unknown	04:30–05:20 (good, 0.83 h)	71.1° 09:35	9.53	31%	103.0°
2036-03-04 Tue	24	—	unknown	04:30–05:20 (good, 0.83 h)	71.1° 09:30	9.48	42%	112.9°
2036-03-05 Wed	26	—	unknown	04:25–05:20 (good, 0.92 h)	71.1° 09:25	9.44	53%	122.3°
2036-03-06 Thu	26	—	unknown	04:20–05:15 (good, 0.92 h)	71.1° 09:20	9.39	64%	130.5°
2036-03-07 Fri	27	—	unknown	04:15–05:15 (good, 1.0 h)	71.1° 09:15	9.34	75%	136.7°
2036-03-08 Sat	27	—	unknown	04:20–05:15 (good, 0.92 h)	71.1° 09:15	9.29	84%	139.5°
2036-03-09 Sun	24	—	unknown	04:15–05:10 (good, 0.92 h)	71.1° 09:10	9.24	92%	138.1°
2036-03-10 Mon	24	—	unknown	04:15–05:10 (good, 0.92 h)	71.1° 09:05	9.2	97%	132.7°
2036-03-11 Tue	23	—	unknown	04:10–05:05 (good, 0.92 h)	71.1° 09:00	9.15	100%	124.7°
2036-03-12 Wed	23	—	unknown	04:10–05:05 (good, 0.92 h)	71.1° 08:55	9.1	100%	115.1°
2036-03-13 Thu	20	—	unknown	04:15–05:05 (good, 0.83 h)	71.1° 08:55	9.05	97%	104.9°
2036-03-14 Fri	18	—	unknown	04:15–05:00 (good, 0.75 h)	71.1° 08:50	9.0	92%	94.6°
2036-03-15 Sat	18	—	unknown	04:35–05:00 (good, 0.42 h)	71.1° 08:45	8.95	85%	84.4°
2036-03-16 Sun	17	—	unknown	04:40–05:00 (good, 0.33 h)	71.1° 08:40	8.9	77%	74.7°
2036-03-17 Mon	18	—	unknown	04:25–04:55 (good, 0.5 h)	71.1° 08:40	8.85	68%	65.6°
2036-03-18 Tue	20	—	unknown	04:00–04:55 (good, 0.92 h)	71.1° 08:35	8.8	58%	57.4°
2036-03-19 Wed	23	—	unknown	03:50–04:55 (good, 1.08 h)	71.1° 08:30	8.74	48%	50.3°
2036-03-20 Thu	25	—	unknown	03:40–04:50 (good, 1.17 h)	71.1° 08:25	8.69	39%	44.7°
2036-03-21 Fri	30	—	unknown	03:20–04:50 (good, 1.5 h)	71.1° 08:20	8.64	30%	41.3°
2036-03-22 Sat	35	—	unknown	03:15–04:45 (good, 1.5 h)	71.1° 08:20	8.59	22%	40.5°
2036-03-23 Sun	39	—	unknown	03:15–04:45 (good, 1.5 h)	71.1° 08:15	8.54	14%	42.6°
2036-03-24 Mon	40	—	unknown	03:10–04:45 (good, 1.58 h)	71.1° 08:10	8.48	8%	47.2°
2036-03-25 Tue	40	—	unknown	03:05–04:40 (good, 1.58 h)	71.1° 08:05	8.43	4%	53.7°
2036-03-26 Wed	42	—	unknown	03:00–04:40 (good, 1.67 h)	71.1° 08:00	8.38	1%	61.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-02-26&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.