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 Triangulum Pinwheel: 02-25 (35), 02-26 (35), 02-27 (33), 02-23 (32), 02-24 (32) — by astronomy; check the weather when the night is within four days.

2043-02-16astronomy score per night — click a bar for that night2043-03-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-02-16 Mon	21	—	unknown	19:30–22:05 (marginal, 2.58 h)	79.2° 16:10	10.21	53%	31.2°
2043-02-17 Tue	17	—	unknown	19:30–21:55 (marginal, 2.42 h)	79.2° 16:10	10.17	64%	43.4°
2043-02-18 Wed	16	—	unknown	19:35–21:45 (marginal, 2.17 h)	79.2° 16:05	10.13	74%	56.1°
2043-02-19 Thu	17	—	unknown	19:35–21:45 (marginal, 2.17 h)	79.2° 16:00	10.09	83%	68.9°
2043-02-20 Fri	19	—	unknown	19:35–21:45 (marginal, 2.17 h)	79.2° 15:55	10.05	90%	81.8°
2043-02-21 Sat	23	—	unknown	19:35–20:20 (good, 0.75 h)	79.2° 15:50	10.0	96%	94.4°
2043-02-22 Sun	27	—	unknown	19:40–20:55 (good, 1.25 h)	79.2° 15:50	9.96	99%	106.9°
2043-02-23 Mon	32	—	unknown	19:40–21:05 (good, 1.42 h)	79.2° 15:45	9.92	100%	119.1°
2043-02-24 Tue	32	—	unknown	19:40–21:00 (good, 1.33 h)	79.2° 15:40	9.88	99%	130.9°
2043-02-25 Wed	35	—	unknown	19:40–21:00 (good, 1.33 h)	79.2° 15:35	9.83	96%	142.1°
2043-02-26 Thu	35	—	unknown	19:40–21:00 (good, 1.33 h)	79.2° 15:30	9.79	91%	152.2°
2043-02-27 Fri	33	—	unknown	19:45–21:00 (good, 1.25 h)	79.2° 15:30	9.74	85%	160.2°
2043-02-28 Sat	31	—	unknown	19:45–20:55 (good, 1.17 h)	79.2° 15:25	9.7	78%	162.8°
2043-03-01 Sun	30	—	unknown	19:45–20:55 (good, 1.17 h)	79.2° 15:20	9.65	70%	158.2°
2043-03-02 Mon	28	—	unknown	19:45–20:50 (good, 1.08 h)	79.2° 15:15	9.61	60%	149.7°
2043-03-03 Tue	26	—	unknown	19:50–20:45 (good, 0.92 h)	79.2° 15:10	9.56	51%	139.4°
2043-03-04 Wed	25	—	unknown	19:50–20:40 (good, 0.83 h)	79.2° 15:10	9.51	41%	128.4°
2043-03-05 Thu	23	—	unknown	19:50–20:35 (good, 0.75 h)	79.2° 15:05	9.47	32%	116.8°
2043-03-06 Fri	21	—	unknown	19:50–20:35 (good, 0.75 h)	79.2° 15:00	9.42	23%	104.8°
2043-03-07 Sat	19	—	unknown	19:55–20:30 (good, 0.58 h)	79.2° 14:55	9.37	15%	92.3°
2043-03-08 Sun	18	—	unknown	19:55–20:25 (good, 0.5 h)	79.2° 14:55	9.33	8%	79.4°
2043-03-09 Mon	16	—	unknown	19:55–20:20 (good, 0.42 h)	79.2° 14:50	9.28	3%	66.1°
2043-03-10 Tue	14	—	unknown	19:55–20:15 (good, 0.33 h)	79.2° 14:45	9.23	0%	52.7°
2043-03-11 Wed	11	—	unknown	20:00–20:15 (good, 0.25 h)	79.2° 14:40	9.18	0%	39.4°
2043-03-12 Thu	10	—	unknown	20:00–20:10 (good, 0.17 h)	79.2° 14:35	9.13	3%	27.0°
2043-03-13 Fri	8	—	unknown	19:25–20:35 (marginal, 1.17 h)	79.2° 14:35	9.08	9%	18.2°
2043-03-14 Sat	6	—	unknown	20:00–20:30 (marginal, 0.5 h)	79.2° 14:30	9.03	17%	19.0°
2043-03-15 Sun	4	—	unknown	20:05–20:25 (marginal, 0.33 h)	79.2° 14:25	8.98	27%	28.2°
2043-03-16 Mon	3	—	unknown	20:05–20:25 (marginal, 0.33 h)	79.2° 14:20	8.93	38%	40.3°
2043-03-17 Tue	2	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:15	8.88	49%	53.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-02-16&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.