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 North America Nebula: 03-05 (32), 03-06 (31), 03-07 (31), 03-03 (30), 03-04 (30) — by astronomy; check the weather when the night is within four days.

2028-02-13astronomy score per night — click a bar for that night2028-03-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-02-13 Sun	12	—	unknown	05:40–05:50 (good, 0.17 h)	87.3° 11:45	10.34	84%	121.8°
2028-02-14 Mon	11	—	unknown	05:40–05:45 (good, 0.08 h)	87.2° 11:40	10.3	75%	116.6°
2028-02-15 Tue	12	—	unknown	05:35–05:45 (good, 0.17 h)	87.2° 11:35	10.27	65%	110.1°
2028-02-16 Wed	13	—	unknown	05:30–05:45 (good, 0.25 h)	87.2° 11:35	10.23	54%	103.0°
2028-02-17 Thu	14	—	unknown	05:25–05:45 (good, 0.33 h)	87.2° 11:30	10.18	44%	95.6°
2028-02-18 Fri	15	—	unknown	05:20–05:40 (good, 0.33 h)	87.3° 11:25	10.14	34%	88.2°
2028-02-19 Sat	17	—	unknown	05:15–05:40 (good, 0.42 h)	87.2° 11:20	10.1	25%	81.0°
2028-02-20 Sun	19	—	unknown	05:00–05:40 (good, 0.67 h)	87.2° 11:20	10.06	17%	74.2°
2028-02-21 Mon	20	—	unknown	05:00–05:35 (good, 0.58 h)	87.2° 11:15	10.02	10%	68.1°
2028-02-22 Tue	22	—	unknown	04:55–05:35 (good, 0.67 h)	87.3° 11:10	9.98	6%	62.7°
2028-02-23 Wed	23	—	unknown	04:50–05:35 (good, 0.75 h)	87.2° 11:05	9.93	2%	58.4°
2028-02-24 Thu	24	—	unknown	04:45–05:35 (good, 0.83 h)	87.2° 11:00	9.89	0%	55.5°
2028-02-25 Fri	24	—	unknown	04:45–05:30 (good, 0.75 h)	87.2° 11:00	9.85	0%	54.2°
2028-02-26 Sat	24	—	unknown	04:40–05:30 (good, 0.83 h)	87.2° 10:55	9.8	2%	54.6°
2028-02-27 Sun	26	—	unknown	04:35–05:30 (good, 0.92 h)	87.3° 10:50	9.76	6%	56.8°
2028-02-28 Mon	26	—	unknown	04:30–05:25 (good, 0.92 h)	87.2° 10:45	9.71	11%	60.6°
2028-02-29 Tue	28	—	unknown	04:25–05:25 (good, 1.0 h)	87.2° 10:40	9.67	18%	65.6°
2028-03-01 Wed	28	—	unknown	04:25–05:25 (good, 1.0 h)	87.2° 10:40	9.62	26%	71.7°
2028-03-02 Thu	29	—	unknown	04:20–05:25 (good, 1.08 h)	87.2° 10:35	9.58	35%	78.6°
2028-03-03 Fri	30	—	unknown	04:15–05:20 (good, 1.08 h)	87.3° 10:30	9.53	45%	86.0°
2028-03-04 Sat	30	—	unknown	04:10–05:20 (good, 1.17 h)	87.2° 10:25	9.48	56%	93.8°
2028-03-05 Sun	32	—	unknown	04:05–05:20 (good, 1.25 h)	87.2° 10:20	9.44	67%	101.7°
2028-03-06 Mon	31	—	unknown	04:15–05:15 (good, 1.0 h)	87.2° 10:20	9.39	77%	109.3°
2028-03-07 Tue	31	—	unknown	04:10–05:15 (good, 1.08 h)	87.3° 10:15	9.34	86%	116.3°
2028-03-08 Wed	29	—	unknown	04:05–05:15 (good, 1.17 h)	87.2° 10:10	9.29	93%	121.8°
2028-03-09 Thu	28	—	unknown	04:05–05:10 (good, 1.08 h)	87.2° 10:05	9.25	98%	125.2°
2028-03-10 Fri	28	—	unknown	04:00–05:10 (good, 1.17 h)	87.2° 10:05	9.2	100%	125.8°
2028-03-11 Sat	28	—	unknown	03:55–05:05 (good, 1.17 h)	87.2° 10:00	9.15	99%	123.5°
2028-03-12 Sun	29	—	unknown	03:55–05:05 (good, 1.17 h)	87.3° 09:55	9.1	95%	118.9°
2028-03-13 Mon	28	—	unknown	03:50–05:05 (good, 1.25 h)	87.2° 09:50	9.05	88%	112.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-02-13&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.