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: 03-22 (39), 03-21 (37), 03-19 (36), 03-20 (36), 03-17 (35) — by astronomy; check the weather when the night is within four days.

2034-02-21astronomy score per night — click a bar for that night2034-03-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-02-21 Tue	15	—	unknown	05:15–05:35 (good, 0.33 h)	71.1° 10:15	10.0	12%	72.2°
2034-02-22 Wed	16	—	unknown	05:10–05:35 (good, 0.42 h)	71.1° 10:10	9.95	20%	83.5°
2034-02-23 Thu	17	—	unknown	05:05–05:35 (good, 0.5 h)	71.1° 10:05	9.91	30%	94.9°
2034-02-24 Fri	17	—	unknown	05:00–05:30 (good, 0.5 h)	71.1° 10:00	9.87	42%	106.0°
2034-02-25 Sat	19	—	unknown	04:55–05:30 (good, 0.58 h)	71.1° 10:00	9.82	53%	116.5°
2034-02-26 Sun	20	—	unknown	04:55–05:30 (good, 0.58 h)	71.1° 09:55	9.78	64%	126.1°
2034-02-27 Mon	21	—	unknown	04:50–05:30 (good, 0.67 h)	71.1° 09:50	9.73	74%	134.1°
2034-02-28 Tue	21	—	unknown	04:45–05:25 (good, 0.67 h)	71.1° 09:45	9.69	83%	139.7°
2034-03-01 Wed	21	—	unknown	04:50–05:25 (good, 0.58 h)	71.1° 09:45	9.64	90%	142.1°
2034-03-02 Thu	19	—	unknown	04:45–05:25 (good, 0.67 h)	71.1° 09:40	9.6	95%	140.8°
2034-03-03 Fri	19	—	unknown	04:45–05:20 (good, 0.58 h)	71.1° 09:35	9.55	99%	136.2°
2034-03-04 Sat	19	—	unknown	04:40–05:20 (good, 0.67 h)	71.1° 09:30	9.51	100%	129.5°
2034-03-05 Sun	20	—	unknown	04:35–05:20 (good, 0.75 h)	71.1° 09:25	9.46	99%	121.4°
2034-03-06 Mon	18	—	unknown	04:35–05:15 (good, 0.67 h)	71.1° 09:25	9.41	97%	112.6°
2034-03-07 Tue	17	—	unknown	04:40–05:15 (good, 0.58 h)	71.1° 09:20	9.36	93%	103.4°
2034-03-08 Wed	16	—	unknown	04:40–05:15 (good, 0.58 h)	71.1° 09:15	9.32	87%	94.1°
2034-03-09 Thu	15	—	unknown	04:40–05:10 (good, 0.5 h)	71.1° 09:10	9.27	80%	84.8°
2034-03-10 Fri	15	—	unknown	04:45–05:10 (good, 0.42 h)	71.1° 09:05	9.22	72%	75.5°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-02-21&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.