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: 02-25 (25), 02-26 (25), 02-23 (23), 02-24 (23), 02-20 (21) — by astronomy; check the weather when the night is within four days.

2042-01-28astronomy score per night — click a bar for that night2042-02-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-01-28 Tue	8	—	unknown	19:10–19:45 (marginal, 0.58 h)	87.3° 12:50	10.88	55%	75.8°
2042-01-29 Wed	7	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.3° 12:45	10.85	65%	81.8°
2042-01-30 Thu	7	—	unknown	19:10–19:35 (marginal, 0.42 h)	87.2° 12:40	10.82	75%	88.2°
2042-01-31 Fri	7	—	unknown	05:45–06:00 (marginal, 0.25 h)	87.3° 12:40	10.79	83%	94.4°
2042-02-01 Sat	6	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.3° 12:35	10.75	90%	100.5°
2042-02-02 Sun	6	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.3° 12:30	10.72	95%	106.0°
2042-02-03 Mon	7	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.3° 12:25	10.69	98%	110.7°
2042-02-04 Tue	7	—	unknown	05:30–05:55 (marginal, 0.42 h)	87.2° 12:25	10.65	100%	114.6°
2042-02-05 Wed	7	—	unknown	05:25–05:55 (marginal, 0.5 h)	87.3° 12:20	10.62	99%	117.3°
2042-02-06 Thu	8	—	unknown	05:20–05:55 (marginal, 0.58 h)	87.3° 12:15	10.58	97%	118.7°
2042-02-07 Fri	8	—	unknown	05:15–05:55 (marginal, 0.67 h)	87.3° 12:10	10.55	93%	118.7°
2042-02-08 Sat	8	—	unknown	05:15–05:55 (marginal, 0.67 h)	87.2° 12:05	10.51	87%	117.4°
2042-02-09 Sun	8	—	unknown	05:10–05:50 (marginal, 0.67 h)	87.3° 12:00	10.47	80%	114.9°
2042-02-10 Mon	9	—	unknown	05:05–05:50 (marginal, 0.75 h)	87.3° 11:55	10.44	72%	111.4°
2042-02-11 Tue	10	—	unknown	05:00–06:20 (marginal, 1.33 h)	87.3° 11:50	10.4	63%	106.9°
2042-02-12 Wed	11	—	unknown	05:45–05:50 (good, 0.08 h)	87.2° 11:45	10.36	54%	101.7°
2042-02-13 Thu	11	—	unknown	05:40–05:45 (good, 0.08 h)	87.3° 11:45	10.32	44%	96.0°
2042-02-14 Fri	12	—	unknown	05:35–05:45 (good, 0.17 h)	87.3° 11:40	10.28	34%	89.9°
2042-02-15 Sat	14	—	unknown	05:25–05:45 (good, 0.33 h)	87.3° 11:35	10.24	24%	83.6°
2042-02-16 Sun	16	—	unknown	05:15–05:45 (good, 0.5 h)	87.3° 11:30	10.2	15%	77.3°
2042-02-17 Mon	17	—	unknown	05:15–05:40 (good, 0.42 h)	87.2° 11:30	10.16	8%	71.4°
2042-02-18 Tue	18	—	unknown	05:10–05:40 (good, 0.5 h)	87.3° 11:25	10.12	3%	66.4°
2042-02-19 Wed	20	—	unknown	05:05–05:40 (good, 0.58 h)	87.3° 11:20	10.08	0%	62.9°
2042-02-20 Thu	21	—	unknown	05:00–05:40 (good, 0.67 h)	87.3° 11:15	10.04	1%	61.2°
2042-02-21 Fri	21	—	unknown	04:55–05:35 (good, 0.67 h)	87.2° 11:10	9.99	4%	61.7°
2042-02-22 Sat	21	—	unknown	04:55–05:35 (good, 0.67 h)	87.2° 11:10	9.95	10%	64.2°
2042-02-23 Sun	23	—	unknown	04:50–05:35 (good, 0.75 h)	87.3° 11:05	9.91	18%	68.5°
2042-02-24 Mon	23	—	unknown	04:45–05:30 (good, 0.75 h)	87.3° 11:00	9.86	28%	73.9°
2042-02-25 Tue	25	—	unknown	04:40–05:30 (good, 0.83 h)	87.3° 10:55	9.82	39%	80.0°
2042-02-26 Wed	25	—	unknown	04:35–05:30 (good, 0.92 h)	87.2° 10:50	9.78	50%	86.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-01-28&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.