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 Seven Sisters: 01-29 (100), 01-30 (100), 01-31 (100), 02-01 (100), 02-02 (100) — by astronomy; check the weather when the night is within four days.

2046-01-29astronomy score per night — click a bar for that night2046-02-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-01-29 Mon	100	—	unknown	19:10–00:45 (good, 5.58 h)	72.6° 19:35	10.85	42%	169.9°
2046-01-30 Tue	100	—	unknown	19:10–00:40 (good, 5.5 h)	72.6° 19:30	10.82	32%	176.7°
2046-01-31 Wed	100	—	unknown	19:15–00:35 (good, 5.33 h)	72.6° 19:25	10.79	22%	164.0°
2046-02-01 Thu	100	—	unknown	19:15–00:35 (good, 5.33 h)	72.6° 19:20	10.75	15%	151.4°
2046-02-02 Fri	100	—	unknown	19:15–00:30 (good, 5.25 h)	72.6° 19:20	10.72	8%	139.0°
2046-02-03 Sat	100	—	unknown	19:15–00:25 (good, 5.17 h)	72.6° 19:15	10.69	4%	126.8°
2046-02-04 Sun	100	—	unknown	19:20–00:20 (good, 5.0 h)	72.6° 19:10	10.65	1%	114.7°
2046-02-05 Mon	100	—	unknown	19:20–00:15 (good, 4.92 h)	72.6° 19:05	10.62	0%	102.7°
2046-02-06 Tue	100	—	unknown	19:20–00:15 (good, 4.92 h)	72.6° 19:00	10.58	1%	90.8°
2046-02-07 Wed	100	—	unknown	19:20–00:10 (good, 4.83 h)	72.6° 19:00	10.54	4%	78.9°
2046-02-08 Thu	100	—	unknown	19:20–00:05 (good, 4.75 h)	72.6° 18:55	10.51	8%	67.1°
2046-02-09 Fri	96	—	unknown	19:25–00:00 (good, 4.58 h)	72.6° 18:50	10.47	14%	55.3°
2046-02-10 Sat	91	—	unknown	19:25–23:55 (good, 4.5 h)	72.6° 18:45	10.43	21%	43.4°
2046-02-11 Sun	83	—	unknown	19:25–23:55 (good, 4.5 h)	72.6° 18:45	10.4	29%	31.4°
2046-02-12 Mon	66	—	unknown	19:25–23:30 (good, 4.08 h)	72.6° 18:40	10.36	38%	19.2°
2046-02-13 Tue	50	—	unknown	19:30–22:55 (good, 3.42 h)	72.6° 18:35	10.32	48%	6.8°
2046-02-14 Wed	36	—	unknown	19:30–00:00 (marginal, 4.5 h)	72.6° 18:30	10.28	58%	6.2°
2046-02-15 Thu	24	—	unknown	19:30–23:45 (marginal, 4.25 h)	72.6° 18:25	10.24	68%	19.3°
2046-02-16 Fri	18	—	unknown	19:30–23:25 (marginal, 3.92 h)	72.6° 18:25	10.2	78%	33.0°
2046-02-17 Sat	20	—	unknown	19:30–23:20 (marginal, 3.83 h)	72.6° 18:20	10.16	87%	47.2°
2046-02-18 Sun	27	—	unknown	19:35–23:25 (marginal, 3.83 h)	72.6° 18:15	10.12	94%	61.9°
2046-02-19 Mon	38	—	unknown	19:35–20:30 (good, 0.92 h)	72.6° 18:10	10.08	98%	76.9°
2046-02-20 Tue	53	—	unknown	19:35–22:00 (good, 2.42 h)	72.6° 18:05	10.03	100%	92.1°
2046-02-21 Wed	68	—	unknown	19:35–22:55 (good, 3.33 h)	72.6° 18:05	9.99	98%	107.4°
2046-02-22 Thu	86	—	unknown	19:40–23:00 (good, 3.33 h)	72.6° 18:00	9.95	94%	122.6°
2046-02-23 Fri	88	—	unknown	19:40–23:00 (good, 3.33 h)	72.6° 17:55	9.91	87%	137.5°
2046-02-24 Sat	88	—	unknown	19:40–22:55 (good, 3.25 h)	72.6° 17:50	9.86	78%	152.0°
2046-02-25 Sun	87	—	unknown	19:40–23:00 (good, 3.33 h)	72.6° 17:50	9.82	68%	166.0°
2046-02-26 Mon	83	—	unknown	19:45–22:55 (good, 3.17 h)	72.6° 17:45	9.77	58%	179.0°
2046-02-27 Tue	82	—	unknown	19:45–22:50 (good, 3.08 h)	72.6° 17:40	9.73	47%	167.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-01-29&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.