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: 03-27 (43), 03-28 (42), 03-29 (42), 03-30 (42), 03-25 (41) — by astronomy; check the weather when the night is within four days.

2034-03-11astronomy score per night — click a bar for that night2034-04-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-03-11 Sat	17	—	unknown	04:30–05:10 (good, 0.67 h)	71.1° 09:05	9.17	63%	66.5°
2034-03-12 Sun	18	—	unknown	04:20–05:05 (good, 0.75 h)	71.1° 09:00	9.12	53%	57.8°
2034-03-13 Mon	20	—	unknown	04:10–05:05 (good, 0.92 h)	71.1° 08:55	9.07	44%	49.9°
2034-03-14 Tue	23	—	unknown	04:05–05:05 (good, 1.0 h)	71.1° 08:50	9.02	34%	43.3°
2034-03-15 Wed	26	—	unknown	03:55–05:00 (good, 1.08 h)	71.1° 08:45	8.97	24%	38.9°
2034-03-16 Thu	31	—	unknown	03:40–05:00 (good, 1.33 h)	71.1° 08:45	8.92	16%	38.0°
2034-03-17 Fri	35	—	unknown	03:40–05:00 (good, 1.33 h)	71.1° 08:40	8.87	8%	41.1°
2034-03-18 Sat	35	—	unknown	03:35–04:55 (good, 1.33 h)	71.1° 08:35	8.82	3%	47.8°
2034-03-19 Sun	36	—	unknown	03:30–04:55 (good, 1.42 h)	71.1° 08:30	8.77	0%	57.0°
2034-03-20 Mon	36	—	unknown	03:25–04:50 (good, 1.42 h)	71.1° 08:30	8.72	0%	67.7°
2034-03-21 Tue	37	—	unknown	03:25–04:50 (good, 1.42 h)	71.1° 08:25	8.67	3%	79.2°
2034-03-22 Wed	39	—	unknown	03:20–04:50 (good, 1.5 h)	71.1° 08:20	8.61	9%	91.0°
2034-03-23 Thu	38	—	unknown	03:15–04:45 (good, 1.5 h)	71.1° 08:15	8.56	17%	102.6°
2034-03-24 Fri	40	—	unknown	03:10–04:45 (good, 1.58 h)	71.1° 08:10	8.51	27%	113.7°
2034-03-25 Sat	41	—	unknown	04:05–05:45 (good, 1.67 h)	71.1° 09:10	8.46	38%	123.8°
2034-03-26 Sun	41	—	unknown	04:05–05:40 (good, 1.58 h)	71.1° 09:05	8.4	49%	132.4°
2034-03-27 Mon	43	—	unknown	04:00–05:40 (good, 1.67 h)	71.1° 09:00	8.35	60%	138.7°
2034-03-28 Tue	42	—	unknown	04:00–05:35 (good, 1.58 h)	71.1° 08:55	8.3	70%	141.9°
2034-03-29 Wed	42	—	unknown	03:55–05:35 (good, 1.67 h)	71.1° 08:50	8.24	79%	141.5°
2034-03-30 Thu	42	—	unknown	03:55–05:35 (good, 1.67 h)	71.1° 08:50	8.19	86%	137.7°
2034-03-31 Fri	38	—	unknown	03:50–05:30 (good, 1.67 h)	71.1° 08:45	8.13	92%	131.5°
2034-04-01 Sat	39	—	unknown	03:50–05:30 (good, 1.67 h)	71.1° 08:40	8.08	97%	123.7°
2034-04-02 Sun	35	—	unknown	03:50–05:25 (good, 1.58 h)	71.1° 08:35	8.02	99%	115.2°
2034-04-03 Mon	32	—	unknown	03:50–05:25 (good, 1.58 h)	71.1° 08:35	7.97	100%	106.1°
2034-04-04 Tue	29	—	unknown	03:55–05:25 (good, 1.5 h)	71.1° 08:30	7.91	99%	96.8°
2034-04-05 Wed	26	—	unknown	04:25–05:20 (good, 0.92 h)	71.1° 08:25	7.86	96%	87.4°
2034-04-06 Thu	24	—	unknown	04:50–05:20 (good, 0.5 h)	71.1° 08:20	7.8	91%	78.2°
2034-04-07 Fri	23	—	unknown	05:05–05:20 (good, 0.25 h)	71.1° 08:15	7.75	85%	69.1°
2034-04-08 Sat	23	—	unknown	05:10–05:15 (good, 0.08 h)	71.1° 08:15	7.69	78%	60.3°
2034-04-09 Sun	25	—	unknown	04:45–05:15 (good, 0.5 h)	71.1° 08:10	7.63	70%	52.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-03-11&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.