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: 01-18 (26), 01-19 (25), 01-20 (23), 01-21 (22), 01-22 (19) — by astronomy; check the weather when the night is within four days.

2034-01-18astronomy score per night — click a bar for that night2034-02-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-01-18 Wed	26	—	unknown	19:00–19:50 (good, 0.83 h)	87.3° 13:30	11.16	3%	69.4°
2034-01-19 Thu	25	—	unknown	19:00–19:45 (good, 0.75 h)	87.3° 13:25	11.13	0%	63.5°
2034-01-20 Fri	23	—	unknown	19:00–19:40 (good, 0.67 h)	87.3° 13:20	11.11	0%	58.8°
2034-01-21 Sat	22	—	unknown	19:00–19:35 (good, 0.58 h)	87.3° 13:20	11.08	3%	55.8°
2034-01-22 Sun	19	—	unknown	19:05–19:30 (good, 0.42 h)	87.3° 13:15	11.05	8%	55.0°
2034-01-23 Mon	17	—	unknown	19:05–19:25 (good, 0.33 h)	87.3° 13:10	11.03	15%	56.6°
2034-01-24 Tue	14	—	unknown	19:05–19:15 (good, 0.17 h)	87.3° 13:05	11.0	24%	60.4°
2034-01-25 Wed	11	—	unknown	18:35–19:55 (marginal, 1.33 h)	87.3° 13:00	10.97	34%	66.0°
2034-01-26 Thu	9	—	unknown	19:10–19:55 (marginal, 0.75 h)	87.3° 13:00	10.94	45%	72.8°
2034-01-27 Fri	8	—	unknown	19:10–19:50 (marginal, 0.67 h)	87.3° 12:55	10.91	57%	80.4°
2034-01-28 Sat	8	—	unknown	19:10–19:45 (marginal, 0.58 h)	87.3° 12:50	10.88	68%	88.3°
2034-01-29 Sun	7	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.3° 12:45	10.85	78%	96.3°
2034-01-30 Mon	7	—	unknown	19:10–19:35 (marginal, 0.42 h)	87.3° 12:40	10.82	86%	104.0°
2034-01-31 Tue	8	—	unknown	19:15–19:35 (marginal, 0.33 h)	87.3° 12:40	10.79	93%	111.0°
2034-02-01 Wed	7	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.3° 12:35	10.76	97%	116.9°
2034-02-02 Thu	7	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.3° 12:30	10.72	100%	121.5°
2034-02-03 Fri	7	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.3° 12:25	10.69	100%	124.2°
2034-02-04 Sat	7	—	unknown	05:30–05:55 (marginal, 0.42 h)	87.3° 12:25	10.65	98%	125.0°
2034-02-05 Sun	8	—	unknown	05:25–05:55 (marginal, 0.5 h)	87.3° 12:20	10.62	94%	123.8°
2034-02-06 Mon	8	—	unknown	05:20–05:55 (marginal, 0.58 h)	87.3° 12:15	10.58	88%	120.9°
2034-02-07 Tue	8	—	unknown	05:15–05:55 (marginal, 0.67 h)	87.3° 12:10	10.55	81%	116.7°
2034-02-08 Wed	8	—	unknown	05:15–05:55 (marginal, 0.67 h)	87.3° 12:05	10.51	73%	111.4°
2034-02-09 Thu	8	—	unknown	05:10–05:50 (marginal, 0.67 h)	87.3° 12:00	10.47	64%	105.5°
2034-02-10 Fri	9	—	unknown	05:05–05:50 (marginal, 0.75 h)	87.3° 11:55	10.44	55%	99.0°
2034-02-11 Sat	10	—	unknown	05:00–06:20 (marginal, 1.33 h)	87.3° 11:50	10.4	46%	92.3°
2034-02-12 Sun	11	—	unknown	05:45–05:50 (good, 0.08 h)	87.3° 11:45	10.36	36%	85.4°
2034-02-13 Mon	11	—	unknown	05:35–05:45 (good, 0.17 h)	87.3° 11:45	10.32	27%	78.5°
2034-02-14 Tue	13	—	unknown	05:30–05:45 (good, 0.25 h)	87.3° 11:40	10.28	18%	71.8°
2034-02-15 Wed	15	—	unknown	05:25–05:45 (good, 0.33 h)	87.3° 11:35	10.24	11%	65.6°
2034-02-16 Thu	17	—	unknown	05:15–05:45 (good, 0.5 h)	87.3° 11:30	10.2	5%	60.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-01-18&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.