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 V1057 Cyg: 04-12 (62), 04-11 (61), 04-09 (59), 04-10 (59), 04-07 (58) — by astronomy; check the weather when the night is within four days.

2027-03-14astronomy score per night — click a bar for that night2027-04-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2027-03-14 Sun	38	—	unknown	03:35–05:05 (good, 1.5 h)	87.3° 09:50	9.04	42%	88.7°
2027-03-15 Mon	38	—	unknown	03:30–05:00 (good, 1.5 h)	87.3° 09:45	8.99	53%	96.6°
2027-03-16 Tue	38	—	unknown	03:30–05:00 (good, 1.5 h)	87.3° 09:40	8.94	64%	104.3°
2027-03-17 Wed	38	—	unknown	03:35–05:00 (good, 1.42 h)	87.3° 09:40	8.89	75%	111.5°
2027-03-18 Thu	38	—	unknown	03:30–04:55 (good, 1.42 h)	87.3° 09:35	8.84	84%	117.6°
2027-03-19 Fri	36	—	unknown	03:25–04:55 (good, 1.5 h)	87.3° 09:30	8.79	92%	122.1°
2027-03-20 Sat	35	—	unknown	03:25–04:55 (good, 1.5 h)	87.3° 09:25	8.73	97%	124.4°
2027-03-21 Sun	34	—	unknown	03:20–04:50 (good, 1.5 h)	87.3° 09:25	8.68	100%	124.2°
2027-03-22 Mon	35	—	unknown	03:20–04:50 (good, 1.5 h)	87.3° 09:20	8.63	100%	121.8°
2027-03-23 Tue	34	—	unknown	03:15–04:45 (good, 1.5 h)	87.3° 09:15	8.58	97%	117.5°
2027-03-24 Wed	34	—	unknown	03:15–04:45 (good, 1.5 h)	87.3° 09:10	8.53	92%	111.8°
2027-03-25 Thu	33	—	unknown	03:10–04:45 (good, 1.58 h)	87.3° 09:05	8.47	86%	105.4°
2027-03-26 Fri	32	—	unknown	03:10–04:40 (good, 1.5 h)	87.3° 09:05	8.42	78%	98.5°
2027-03-27 Sat	33	—	unknown	04:05–05:40 (good, 1.58 h)	87.3° 10:00	8.37	70%	91.6°
2027-03-28 Sun	35	—	unknown	03:55–05:40 (good, 1.75 h)	87.3° 09:55	8.31	60%	84.7°
2027-03-29 Mon	37	—	unknown	03:50–05:35 (good, 1.75 h)	87.3° 09:50	8.26	51%	78.1°
2027-03-30 Tue	40	—	unknown	03:35–05:35 (good, 2.0 h)	87.3° 09:45	8.2	42%	71.9°
2027-03-31 Wed	45	—	unknown	03:30–05:30 (good, 2.0 h)	87.3° 09:45	8.15	32%	66.3°
2027-04-01 Thu	49	—	unknown	03:25–05:30 (good, 2.08 h)	87.3° 09:40	8.1	24%	61.6°
2027-04-02 Fri	52	—	unknown	03:20–05:30 (good, 2.17 h)	87.3° 09:35	8.04	16%	58.0°
2027-04-03 Sat	54	—	unknown	03:15–05:25 (good, 2.17 h)	87.3° 09:30	7.99	10%	55.8°
2027-04-04 Sun	55	—	unknown	03:15–05:25 (good, 2.17 h)	87.3° 09:30	7.93	5%	55.5°
2027-04-05 Mon	55	—	unknown	03:10–05:20 (good, 2.17 h)	87.3° 09:25	7.87	1%	57.0°
2027-04-06 Tue	56	—	unknown	03:05–05:20 (good, 2.25 h)	87.3° 09:20	7.82	0%	60.5°
2027-04-07 Wed	58	—	unknown	03:00–05:20 (good, 2.33 h)	87.3° 09:15	7.76	1%	65.5°
2027-04-08 Thu	58	—	unknown	02:55–05:15 (good, 2.33 h)	87.3° 09:10	7.71	5%	71.9°
2027-04-09 Fri	59	—	unknown	02:55–05:15 (good, 2.33 h)	87.3° 09:10	7.65	10%	79.2°
2027-04-10 Sat	59	—	unknown	02:50–05:10 (good, 2.33 h)	87.3° 09:05	7.59	18%	87.0°
2027-04-11 Sun	61	—	unknown	02:45–05:10 (good, 2.42 h)	87.3° 09:00	7.54	28%	94.9°
2027-04-12 Mon	62	—	unknown	02:40–05:10 (good, 2.5 h)	87.3° 08:55	7.48	38%	102.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2027-03-14&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.