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: 01-15 (31), 01-16 (30), 01-17 (26), 01-18 (23), 01-19 (21) — by astronomy; check the weather when the night is within four days.

2048-01-15astronomy score per night — click a bar for that night2048-02-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2048-01-15 Wed	31	—	unknown	18:55–20:05 (good, 1.17 h)	87.2° 13:45	11.23	0%	62.9°
2048-01-16 Thu	30	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:40	11.21	3%	57.3°
2048-01-17 Fri	26	—	unknown	19:00–19:55 (good, 0.92 h)	87.2° 13:35	11.19	8%	53.9°
2048-01-18 Sat	23	—	unknown	19:00–19:45 (good, 0.75 h)	87.2° 13:30	11.16	14%	52.8°
2048-01-19 Sun	21	—	unknown	19:00–19:35 (good, 0.58 h)	87.1° 13:25	11.14	22%	53.9°
2048-01-20 Mon	17	—	unknown	19:00–19:25 (good, 0.42 h)	87.2° 13:25	11.12	31%	57.0°
2048-01-21 Tue	15	—	unknown	19:00–19:15 (good, 0.25 h)	87.2° 13:20	11.09	41%	61.5°
2048-01-22 Wed	12	—	unknown	19:05–20:10 (marginal, 1.08 h)	87.2° 13:15	11.06	50%	67.1°
2048-01-23 Thu	11	—	unknown	19:05–20:05 (marginal, 1.0 h)	87.2° 13:10	11.04	60%	73.5°
2048-01-24 Fri	10	—	unknown	19:05–20:00 (marginal, 0.92 h)	87.1° 13:10	11.01	69%	80.3°
2048-01-25 Sat	9	—	unknown	19:05–19:55 (marginal, 0.83 h)	87.2° 13:05	10.98	77%	87.4°
2048-01-26 Sun	9	—	unknown	19:05–19:55 (marginal, 0.83 h)	87.2° 13:00	10.95	84%	94.6°
2048-01-27 Mon	8	—	unknown	19:10–19:50 (marginal, 0.67 h)	87.2° 12:55	10.92	91%	101.8°
2048-01-28 Tue	8	—	unknown	19:10–19:45 (marginal, 0.58 h)	87.2° 12:50	10.89	96%	108.7°
2048-01-29 Wed	8	—	unknown	19:10–19:45 (marginal, 0.58 h)	87.2° 12:50	10.86	99%	115.1°
2048-01-30 Thu	9	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.2° 12:45	10.83	100%	120.6°
2048-01-31 Fri	8	—	unknown	19:15–19:35 (marginal, 0.33 h)	87.2° 12:40	10.8	99%	124.7°
2048-02-01 Sat	8	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:35	10.77	96%	126.9°
2048-02-02 Sun	8	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.1° 12:30	10.74	90%	126.8°
2048-02-03 Mon	8	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.2° 12:30	10.7	83%	124.4°
2048-02-04 Tue	8	—	unknown	05:30–05:55 (marginal, 0.42 h)	87.2° 12:25	10.67	74%	119.8°
2048-02-05 Wed	8	—	unknown	05:25–05:55 (marginal, 0.5 h)	87.2° 12:20	10.63	63%	113.6°
2048-02-06 Thu	8	—	unknown	05:20–05:55 (marginal, 0.58 h)	87.2° 12:15	10.6	52%	106.2°
2048-02-07 Fri	8	—	unknown	05:20–05:55 (marginal, 0.58 h)	87.1° 12:15	10.56	41%	98.0°
2048-02-08 Sat	9	—	unknown	05:15–06:25 (marginal, 1.17 h)	87.2° 12:10	10.53	30%	89.5°
2048-02-09 Sun	10	—	unknown	05:10–06:25 (marginal, 1.25 h)	87.2° 12:05	10.49	20%	80.9°
2048-02-10 Mon	11	—	unknown	05:45–05:50 (good, 0.08 h)	87.2° 12:00	10.45	12%	72.8°
2048-02-11 Tue	12	—	unknown	05:40–05:50 (good, 0.17 h)	87.2° 11:55	10.41	5%	65.4°
2048-02-12 Wed	13	—	unknown	05:35–05:50 (good, 0.25 h)	87.2° 11:50	10.38	2%	59.3°
2048-02-13 Thu	14	—	unknown	05:30–05:50 (good, 0.33 h)	87.2° 11:45	10.34	0%	55.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-01-15&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.