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: 03-14 (38), 03-15 (38), 03-16 (38), 03-11 (36), 03-12 (36) — by astronomy; check the weather when the night is within four days.

2038-02-16astronomy score per night — click a bar for that night2038-03-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-02-16 Tue	16	—	unknown	05:30–05:45 (good, 0.25 h)	87.3° 11:30	10.2	90%	111.1°
2038-02-17 Wed	13	—	unknown	05:25–05:40 (good, 0.25 h)	87.2° 11:25	10.16	96%	115.3°
2038-02-18 Thu	14	—	unknown	05:20–05:40 (good, 0.33 h)	87.3° 11:25	10.12	99%	117.9°
2038-02-19 Fri	15	—	unknown	05:20–05:40 (good, 0.33 h)	87.3° 11:20	10.08	100%	118.7°
2038-02-20 Sat	16	—	unknown	05:15–05:40 (good, 0.42 h)	87.3° 11:15	10.04	98%	117.5°
2038-02-21 Sun	15	—	unknown	05:15–05:35 (good, 0.33 h)	87.3° 11:10	10.0	92%	114.2°
2038-02-22 Mon	15	—	unknown	05:15–05:35 (good, 0.33 h)	87.3° 11:10	9.95	85%	109.4°
2038-02-23 Tue	16	—	unknown	05:10–05:35 (good, 0.42 h)	87.3° 11:05	9.91	76%	103.5°
2038-02-24 Wed	16	—	unknown	05:05–05:30 (good, 0.42 h)	87.3° 11:00	9.87	65%	97.0°
2038-02-25 Thu	18	—	unknown	05:00–05:30 (good, 0.5 h)	87.3° 10:55	9.82	54%	90.4°
2038-02-26 Fri	20	—	unknown	04:50–05:30 (good, 0.67 h)	87.3° 10:50	9.78	43%	83.8°
2038-02-27 Sat	21	—	unknown	04:45–05:30 (good, 0.75 h)	87.3° 10:50	9.73	32%	77.7°
2038-02-28 Sun	23	—	unknown	04:35–05:25 (good, 0.83 h)	87.3° 10:45	9.69	23%	72.2°
2038-03-01 Mon	27	—	unknown	04:25–05:25 (good, 1.0 h)	87.3° 10:40	9.64	15%	67.7°
2038-03-02 Tue	29	—	unknown	04:20–05:25 (good, 1.08 h)	87.3° 10:35	9.6	9%	64.2°
2038-03-03 Wed	28	—	unknown	04:20–05:20 (good, 1.0 h)	87.2° 10:30	9.55	4%	62.0°
2038-03-04 Thu	29	—	unknown	04:15–05:20 (good, 1.08 h)	87.3° 10:30	9.5	1%	61.2°
2038-03-05 Fri	31	—	unknown	04:10–05:20 (good, 1.17 h)	87.3° 10:25	9.46	0%	61.9°
2038-03-06 Sat	31	—	unknown	04:05–05:15 (good, 1.17 h)	87.3° 10:20	9.41	1%	63.8°
2038-03-07 Sun	32	—	unknown	04:00–05:15 (good, 1.25 h)	87.3° 10:15	9.36	4%	66.9°
2038-03-08 Mon	33	—	unknown	04:00–05:15 (good, 1.25 h)	87.3° 10:15	9.32	8%	70.9°
2038-03-09 Tue	33	—	unknown	03:55–05:10 (good, 1.25 h)	87.3° 10:10	9.27	14%	75.6°
2038-03-10 Wed	34	—	unknown	03:50–05:10 (good, 1.33 h)	87.3° 10:05	9.22	21%	80.9°
2038-03-11 Thu	36	—	unknown	03:45–05:10 (good, 1.42 h)	87.3° 10:00	9.17	29%	86.5°
2038-03-12 Fri	36	—	unknown	03:40–05:05 (good, 1.42 h)	87.3° 09:55	9.12	38%	92.3°
2038-03-13 Sat	36	—	unknown	03:40–05:05 (good, 1.42 h)	87.3° 09:55	9.07	48%	98.1°
2038-03-14 Sun	38	—	unknown	03:35–05:05 (good, 1.5 h)	87.3° 09:50	9.02	58%	103.7°
2038-03-15 Mon	38	—	unknown	03:30–05:00 (good, 1.5 h)	87.3° 09:45	8.97	68%	109.0°
2038-03-16 Tue	38	—	unknown	03:35–05:00 (good, 1.42 h)	87.3° 09:40	8.92	78%	113.5°
2038-03-17 Wed	34	—	unknown	03:35–05:00 (good, 1.42 h)	87.2° 09:35	8.87	86%	116.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-02-16&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.