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: 02-27 (26), 02-28 (26), 02-24 (24), 02-25 (24), 02-26 (24) — by astronomy; check the weather when the night is within four days.

2028-01-30astronomy score per night — click a bar for that night2028-02-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-01-30 Sun	9	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.2° 12:45	10.84	16%	55.0°
2028-01-31 Mon	8	—	unknown	19:15–19:35 (marginal, 0.33 h)	87.3° 12:40	10.81	23%	57.5°
2028-02-01 Tue	8	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:35	10.77	32%	61.6°
2028-02-02 Wed	8	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:30	10.74	41%	67.0°
2028-02-03 Thu	8	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.2° 12:30	10.71	51%	73.4°
2028-02-04 Fri	8	—	unknown	05:30–05:55 (marginal, 0.42 h)	87.3° 12:25	10.67	62%	80.6°
2028-02-05 Sat	8	—	unknown	05:25–05:55 (marginal, 0.5 h)	87.3° 12:20	10.64	72%	88.4°
2028-02-06 Sun	9	—	unknown	05:25–05:55 (marginal, 0.5 h)	87.2° 12:15	10.6	81%	96.5°
2028-02-07 Mon	9	—	unknown	05:20–06:25 (marginal, 1.08 h)	87.2° 12:15	10.57	90%	104.7°
2028-02-08 Tue	9	—	unknown	05:15–05:55 (marginal, 0.67 h)	87.2° 12:10	10.53	96%	112.4°
2028-02-09 Wed	9	—	unknown	05:10–05:50 (marginal, 0.67 h)	87.3° 12:05	10.49	99%	119.0°
2028-02-10 Thu	9	—	unknown	05:05–05:50 (marginal, 0.75 h)	87.2° 12:00	10.46	100%	123.7°
2028-02-11 Fri	9	—	unknown	05:05–06:20 (marginal, 1.25 h)	87.2° 11:55	10.42	97%	125.8°
2028-02-12 Sat	10	—	unknown	05:45–05:50 (good, 0.08 h)	87.2° 11:50	10.38	92%	125.1°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-01-30&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.