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: 12-30 (56), 12-31 (55), 01-01 (55), 01-02 (54), 01-03 (52) — by astronomy; check the weather when the night is within four days.

2031-12-29astronomy score per night — click a bar for that night2032-01-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-12-29 Mon	49	—	unknown	18:40–20:55 (good, 2.25 h)	87.3° 14:50	11.48	98%	115.1°
2031-12-30 Tue	56	—	unknown	18:40–20:55 (good, 2.25 h)	87.3° 14:45	11.47	96%	120.3°
2031-12-31 Wed	55	—	unknown	18:45–20:55 (good, 2.17 h)	87.3° 14:40	11.46	91%	124.2°
2032-01-01 Thu	55	—	unknown	18:45–20:55 (good, 2.17 h)	87.3° 14:40	11.45	85%	126.7°
2032-01-02 Fri	54	—	unknown	18:45–20:55 (good, 2.17 h)	87.3° 14:35	11.44	77%	127.3°
2032-01-03 Sat	52	—	unknown	18:45–20:50 (good, 2.08 h)	87.3° 14:30	11.43	69%	126.1°
2032-01-04 Sun	50	—	unknown	18:45–20:45 (good, 2.0 h)	87.3° 14:25	11.42	60%	123.0°
2032-01-05 Mon	48	—	unknown	18:45–20:40 (good, 1.92 h)	87.3° 14:20	11.41	50%	118.4°
2032-01-06 Tue	47	—	unknown	18:45–20:40 (good, 1.92 h)	87.3° 14:20	11.39	40%	112.4°
2032-01-07 Wed	44	—	unknown	18:50–20:35 (good, 1.75 h)	87.3° 14:15	11.38	30%	105.2°
2032-01-08 Thu	43	—	unknown	18:50–20:30 (good, 1.67 h)	87.3° 14:10	11.36	20%	97.2°
2032-01-09 Fri	41	—	unknown	18:50–20:25 (good, 1.58 h)	87.3° 14:05	11.35	12%	88.7°
2032-01-10 Sat	40	—	unknown	18:50–20:25 (good, 1.58 h)	87.3° 14:05	11.33	5%	79.9°
2032-01-11 Sun	38	—	unknown	18:50–20:20 (good, 1.5 h)	87.3° 14:00	11.31	1%	71.4°
2032-01-12 Mon	35	—	unknown	18:55–20:15 (good, 1.33 h)	87.3° 13:55	11.3	0%	63.7°
2032-01-13 Tue	34	—	unknown	18:55–20:10 (good, 1.25 h)	87.3° 13:50	11.28	2%	57.6°
2032-01-14 Wed	31	—	unknown	18:55–20:05 (good, 1.17 h)	87.3° 13:45	11.26	7%	53.8°
2032-01-15 Thu	28	—	unknown	18:55–19:55 (good, 1.0 h)	87.3° 13:45	11.23	14%	52.8°
2032-01-16 Fri	24	—	unknown	18:55–19:50 (good, 0.92 h)	87.3° 13:40	11.21	23%	54.6°
2032-01-17 Sat	19	—	unknown	19:00–19:35 (good, 0.58 h)	87.3° 13:35	11.19	33%	58.7°
2032-01-18 Sun	16	—	unknown	19:00–19:25 (good, 0.42 h)	87.3° 13:30	11.17	44%	64.5°
2032-01-19 Mon	14	—	unknown	19:00–19:05 (good, 0.08 h)	87.3° 13:25	11.14	55%	71.2°
2032-01-20 Tue	13	—	unknown	19:00–20:15 (marginal, 1.25 h)	87.3° 13:25	11.12	65%	78.4°
2032-01-21 Wed	12	—	unknown	19:00–20:10 (marginal, 1.17 h)	87.3° 13:20	11.09	74%	85.9°
2032-01-22 Thu	12	—	unknown	19:05–20:10 (marginal, 1.08 h)	87.3° 13:15	11.07	82%	93.3°
2032-01-23 Fri	12	—	unknown	19:05–20:05 (marginal, 1.0 h)	87.3° 13:10	11.04	89%	100.6°
2032-01-24 Sat	12	—	unknown	18:30–20:00 (marginal, 1.5 h)	87.3° 13:10	11.01	94%	107.4°
2032-01-25 Sun	12	—	unknown	18:35–20:00 (marginal, 1.42 h)	87.3° 13:05	10.99	98%	113.7°
2032-01-26 Mon	12	—	unknown	18:35–19:55 (marginal, 1.33 h)	87.3° 13:00	10.96	100%	119.1°
2032-01-27 Tue	11	—	unknown	19:10–19:50 (marginal, 0.67 h)	87.3° 12:55	10.93	100%	123.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-12-29&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.