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: 01-17 (100), 01-18 (100), 01-19 (100), 01-20 (100), 01-21 (100) — by astronomy; check the weather when the night is within four days.

2033-01-14astronomy score per night — click a bar for that night2033-02-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-01-14 Fri	40	—	unknown	18:55–01:20 (marginal, 6.42 h)	72.6° 20:30	11.24	99%	49.0°
2033-01-15 Sat	58	—	unknown	18:55–19:50 (good, 0.92 h)	72.6° 20:30	11.22	100%	61.4°
2033-01-16 Sun	75	—	unknown	18:55–22:30 (good, 3.58 h)	72.6° 20:25	11.2	98%	73.5°
2033-01-17 Mon	100	—	unknown	19:00–23:55 (good, 4.92 h)	72.6° 20:20	11.17	94%	85.6°
2033-01-18 Tue	100	—	unknown	19:00–01:00 (good, 6.0 h)	72.6° 20:15	11.15	89%	97.4°
2033-01-19 Wed	100	—	unknown	19:00–01:10 (good, 6.17 h)	72.6° 20:10	11.12	83%	109.2°
2033-01-20 Thu	100	—	unknown	19:00–01:10 (good, 6.17 h)	72.6° 20:10	11.1	75%	120.9°
2033-01-21 Fri	100	—	unknown	19:05–01:10 (good, 6.08 h)	72.6° 20:05	11.07	67%	132.6°
2033-01-22 Sat	100	—	unknown	19:05–01:05 (good, 6.0 h)	72.6° 20:00	11.05	58%	144.4°
2033-01-23 Sun	100	—	unknown	19:05–01:05 (good, 6.0 h)	72.6° 19:55	11.02	48%	156.1°
2033-01-24 Mon	100	—	unknown	19:05–01:05 (good, 6.0 h)	72.6° 19:50	10.99	38%	167.3°
2033-01-25 Tue	100	—	unknown	19:05–01:00 (good, 5.92 h)	72.6° 19:50	10.96	29%	172.6°
2033-01-26 Wed	100	—	unknown	19:10–00:55 (good, 5.75 h)	72.6° 19:45	10.93	20%	163.2°
2033-01-27 Thu	100	—	unknown	19:10–00:50 (good, 5.67 h)	72.6° 19:40	10.91	12%	150.3°
2033-01-28 Fri	100	—	unknown	19:10–00:45 (good, 5.58 h)	72.6° 19:35	10.87	6%	136.6°
2033-01-29 Sat	100	—	unknown	19:10–00:45 (good, 5.58 h)	72.6° 19:35	10.84	2%	122.3°
2033-01-30 Sun	100	—	unknown	19:10–00:40 (good, 5.5 h)	72.6° 19:30	10.81	0%	107.6°
2033-01-31 Mon	100	—	unknown	19:15–00:35 (good, 5.33 h)	72.6° 19:25	10.78	2%	92.8°
2033-02-01 Tue	100	—	unknown	19:15–00:30 (good, 5.25 h)	72.6° 19:20	10.75	6%	77.9°
2033-02-02 Wed	100	—	unknown	19:15–00:30 (good, 5.25 h)	72.6° 19:15	10.71	13%	63.1°
2033-02-03 Thu	92	—	unknown	19:15–00:25 (good, 5.17 h)	72.6° 19:15	10.68	22%	48.6°
2033-02-04 Fri	83	—	unknown	19:20–00:20 (good, 5.0 h)	72.6° 19:10	10.65	32%	34.5°
2033-02-05 Sat	69	—	unknown	19:20–23:55 (good, 4.58 h)	72.6° 19:05	10.61	43%	21.0°
2033-02-06 Sun	51	—	unknown	19:50–22:15 (good, 2.42 h)	72.6° 19:00	10.58	54%	9.4°
2033-02-07 Mon	35	—	unknown	19:20–00:25 (marginal, 5.08 h)	72.6° 18:55	10.54	65%	10.1°
2033-02-08 Tue	24	—	unknown	19:20–00:10 (marginal, 4.83 h)	72.6° 18:55	10.5	74%	21.3°
2033-02-09 Wed	20	—	unknown	19:25–23:50 (marginal, 4.42 h)	72.6° 18:50	10.47	82%	33.6°
2033-02-10 Thu	23	—	unknown	19:25–23:45 (marginal, 4.33 h)	72.6° 18:45	10.43	89%	45.9°
2033-02-11 Fri	30	—	unknown	19:25–23:45 (marginal, 4.33 h)	72.6° 18:40	10.39	95%	58.1°
2033-02-12 Sat	39	—	unknown	19:25–19:55 (good, 0.5 h)	72.6° 18:35	10.35	98%	70.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-01-14&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.