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: 02-18 (78), 03-02 (69), 03-03 (69), 03-04 (67), 03-05 (66) — by astronomy; check the weather when the night is within four days.

2048-02-18astronomy score per night — click a bar for that night2048-03-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2048-02-20 Thu	51	—	unknown	19:35–22:55 (good, 3.33 h)	72.6° 18:10	10.05	42%	7.2°
2048-02-21 Fri	38	—	unknown	19:35–20:45 (good, 1.17 h)	72.6° 18:05	10.01	51%	4.9°
2048-02-22 Sat	28	—	unknown	19:40–23:30 (marginal, 3.83 h)	72.6° 18:00	9.97	61%	16.6°
2048-02-23 Sun	20	—	unknown	19:40–23:10 (marginal, 3.5 h)	72.6° 17:55	9.93	70%	28.6°
2048-02-24 Mon	19	—	unknown	19:40–23:00 (marginal, 3.33 h)	72.6° 17:55	9.88	78%	40.7°
2048-02-25 Tue	21	—	unknown	19:40–23:00 (marginal, 3.33 h)	72.6° 17:50	9.84	86%	53.1°
2048-02-26 Wed	26	—	unknown	19:40–23:00 (marginal, 3.33 h)	72.6° 17:45	9.8	92%	65.7°
2048-02-27 Thu	33	—	unknown	19:45–20:20 (good, 0.58 h)	72.6° 17:40	9.75	97%	78.8°
2048-02-28 Fri	42	—	unknown	19:45–21:35 (good, 1.83 h)	72.6° 17:40	9.71	99%	92.1°
2048-02-29 Sat	53	—	unknown	19:45–22:25 (good, 2.67 h)	72.6° 17:35	9.66	100%	105.7°
2048-03-01 Sun	63	—	unknown	19:45–22:30 (good, 2.75 h)	72.6° 17:30	9.62	98%	119.6°
2048-03-02 Mon	69	—	unknown	19:50–22:30 (good, 2.67 h)	72.6° 17:25	9.57	93%	133.7°
2048-03-03 Tue	69	—	unknown	19:50–22:25 (good, 2.58 h)	72.6° 17:20	9.52	86%	147.9°
2048-03-04 Wed	67	—	unknown	19:50–22:30 (good, 2.67 h)	72.6° 17:20	9.48	77%	162.2°
2048-03-05 Thu	66	—	unknown	19:50–22:25 (good, 2.58 h)	72.6° 17:15	9.43	67%	176.3°
2048-03-06 Fri	62	—	unknown	19:55–22:20 (good, 2.42 h)	72.6° 17:10	9.38	56%	169.2°
2048-03-07 Sat	61	—	unknown	19:55–22:15 (good, 2.33 h)	72.6° 17:05	9.34	44%	155.2°
2048-03-08 Sun	58	—	unknown	19:55–22:15 (good, 2.33 h)	72.6° 17:00	9.29	34%	141.2°
2048-03-09 Mon	56	—	unknown	19:55–22:10 (good, 2.25 h)	72.6° 17:00	9.24	23%	127.3°
2048-03-10 Tue	53	—	unknown	20:00–22:05 (good, 2.08 h)	72.6° 16:55	9.19	15%	113.6°
2048-03-11 Wed	51	—	unknown	20:00–22:00 (good, 2.0 h)	72.6° 16:50	9.14	8%	100.0°
2048-03-12 Thu	50	—	unknown	20:00–22:00 (good, 2.0 h)	72.6° 16:45	9.09	3%	86.7°
2048-03-13 Fri	47	—	unknown	20:00–21:55 (good, 1.92 h)	72.6° 16:45	9.04	1%	73.5°
2048-03-14 Sat	45	—	unknown	20:00–21:50 (good, 1.83 h)	72.6° 16:40	8.99	0%	60.6°
2048-03-15 Sun	43	—	unknown	20:05–21:45 (good, 1.67 h)	72.6° 16:35	8.94	2%	47.9°
2048-03-16 Mon	40	—	unknown	20:05–21:40 (good, 1.58 h)	72.6° 16:30	8.89	6%	35.5°
2048-03-17 Tue	35	—	unknown	20:05–21:35 (good, 1.5 h)	72.6° 16:25	8.84	11%	23.2°
2048-03-18 Wed	30	—	unknown	20:05–21:25 (good, 1.33 h)	72.6° 16:25	8.79	18%	11.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-02-18&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.