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: 02-01 (100), 02-02 (100), 02-03 (100), 02-04 (100), 02-05 (100) — by astronomy; check the weather when the night is within four days.

2048-01-21astronomy score per night — click a bar for that night2048-02-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2048-01-21 Tue	85	—	unknown	19:00–01:20 (good, 6.33 h)	72.6° 20:05	11.09	41%	38.9°
2048-01-22 Wed	69	—	unknown	19:05–00:50 (good, 5.75 h)	72.6° 20:05	11.06	50%	26.8°
2048-01-23 Thu	57	—	unknown	19:05–01:35 (marginal, 6.5 h)	72.6° 20:00	11.04	60%	15.0°
2048-01-24 Fri	40	—	unknown	19:05–01:25 (marginal, 6.33 h)	72.6° 19:55	11.01	69%	3.3°
2048-01-25 Sat	28	—	unknown	19:05–01:10 (marginal, 6.08 h)	72.6° 19:50	10.98	77%	8.8°
2048-01-26 Sun	21	—	unknown	19:05–00:45 (marginal, 5.67 h)	72.6° 19:45	10.95	84%	20.7°
2048-01-27 Mon	18	—	unknown	19:10–22:10 (marginal, 3.0 h)	72.6° 19:45	10.92	91%	32.8°
2048-01-28 Tue	26	—	unknown	19:10–00:25 (marginal, 5.25 h)	72.6° 19:40	10.89	96%	45.1°
2048-01-29 Wed	37	—	unknown	19:10–00:35 (marginal, 5.42 h)	72.6° 19:35	10.86	99%	57.6°
2048-01-30 Thu	54	—	unknown	19:10–20:35 (good, 1.42 h)	72.6° 19:30	10.83	100%	70.4°
2048-01-31 Fri	73	—	unknown	19:15–22:35 (good, 3.33 h)	72.6° 19:30	10.8	99%	83.5°
2048-02-01 Sat	100	—	unknown	19:15–23:55 (good, 4.67 h)	72.6° 19:25	10.77	96%	96.7°
2048-02-02 Sun	100	—	unknown	19:15–00:15 (good, 5.0 h)	72.6° 19:20	10.74	90%	110.2°
2048-02-03 Mon	100	—	unknown	19:15–00:20 (good, 5.08 h)	72.6° 19:15	10.7	83%	123.8°
2048-02-04 Tue	100	—	unknown	19:15–00:15 (good, 5.0 h)	72.6° 19:10	10.67	74%	137.6°
2048-02-05 Wed	100	—	unknown	19:20–00:15 (good, 4.92 h)	72.6° 19:10	10.63	63%	151.5°
2048-02-06 Thu	100	—	unknown	19:20–00:15 (good, 4.92 h)	72.6° 19:05	10.6	52%	165.5°
2048-02-07 Fri	100	—	unknown	19:20–00:10 (good, 4.83 h)	72.6° 19:00	10.56	41%	178.9°
2048-02-08 Sat	100	—	unknown	19:20–00:05 (good, 4.75 h)	72.6° 18:55	10.53	30%	166.1°
2048-02-09 Sun	100	—	unknown	19:25–00:05 (good, 4.67 h)	72.6° 18:50	10.49	20%	151.9°
2048-02-10 Mon	100	—	unknown	19:25–00:00 (good, 4.58 h)	72.6° 18:50	10.45	12%	137.6°
2048-02-11 Tue	100	—	unknown	19:25–23:55 (good, 4.5 h)	72.6° 18:45	10.41	5%	123.5°
2048-02-12 Wed	100	—	unknown	19:25–23:50 (good, 4.42 h)	72.6° 18:40	10.38	2%	109.4°
2048-02-13 Thu	100	—	unknown	19:25–23:50 (good, 4.42 h)	72.6° 18:35	10.34	0%	95.6°
2048-02-14 Fri	100	—	unknown	19:30–23:45 (good, 4.25 h)	72.6° 18:35	10.3	1%	82.1°
2048-02-15 Sat	100	—	unknown	19:30–23:40 (good, 4.17 h)	72.6° 18:30	10.26	4%	68.8°
2048-02-16 Sun	97	—	unknown	19:30–23:35 (good, 4.08 h)	72.6° 18:25	10.22	10%	55.9°
2048-02-17 Mon	93	—	unknown	19:30–23:30 (good, 4.0 h)	72.6° 18:20	10.18	16%	43.4°
2048-02-18 Tue	78	—	unknown	19:35–23:30 (good, 3.92 h)	72.6° 18:15	10.14	24%	31.1°
2048-02-19 Wed	64	—	unknown	19:35–23:10 (good, 3.58 h)	72.6° 18:15	10.1	33%	19.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-01-21&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.