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: 01-23 (100), 01-24 (100), 01-25 (100), 01-26 (100), 01-27 (100) — by astronomy; check the weather when the night is within four days.

2038-01-18astronomy score per night — click a bar for that night2038-02-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-01-18 Mon	32	—	unknown	19:00–23:30 (marginal, 4.5 h)	79.2° 18:05	11.15	94%	60.2°
2038-01-19 Tue	41	—	unknown	19:00–19:35 (good, 0.58 h)	79.2° 18:00	11.13	98%	72.3°
2038-01-20 Wed	55	—	unknown	19:00–21:15 (good, 2.25 h)	79.2° 17:55	11.11	100%	84.8°
2038-01-21 Thu	71	—	unknown	19:00–22:35 (good, 3.58 h)	79.2° 17:55	11.08	99%	97.7°
2038-01-22 Fri	86	—	unknown	19:05–23:00 (good, 3.92 h)	79.2° 17:50	11.05	96%	110.6°
2038-01-23 Sat	100	—	unknown	19:05–23:05 (good, 4.0 h)	79.2° 17:45	11.03	90%	123.4°
2038-01-24 Sun	100	—	unknown	19:05–23:05 (good, 4.0 h)	79.2° 17:40	11.0	82%	135.6°
2038-01-25 Mon	100	—	unknown	19:05–23:05 (good, 4.0 h)	79.2° 17:35	10.97	72%	146.3°
2038-01-26 Tue	100	—	unknown	19:10–23:05 (good, 3.92 h)	79.2° 17:35	10.94	61%	153.8°
2038-01-27 Wed	100	—	unknown	19:10–23:00 (good, 3.83 h)	79.2° 17:30	10.91	50%	155.1°
2038-01-28 Thu	99	—	unknown	19:10–22:55 (good, 3.75 h)	79.2° 17:25	10.88	39%	149.7°
2038-01-29 Fri	97	—	unknown	19:10–22:55 (good, 3.75 h)	79.2° 17:20	10.85	28%	140.4°
2038-01-30 Sat	96	—	unknown	19:10–22:50 (good, 3.67 h)	79.2° 17:15	10.82	19%	129.4°
2038-01-31 Sun	93	—	unknown	19:15–22:45 (good, 3.5 h)	79.2° 17:15	10.79	11%	117.8°
2038-02-01 Mon	91	—	unknown	19:15–22:40 (good, 3.42 h)	79.2° 17:10	10.75	6%	106.1°
2038-02-02 Tue	88	—	unknown	19:15–22:40 (good, 3.42 h)	79.2° 17:05	10.72	2%	94.3°
2038-02-03 Wed	87	—	unknown	19:15–22:35 (good, 3.33 h)	79.2° 17:00	10.69	0%	82.7°
2038-02-04 Thu	84	—	unknown	19:20–22:30 (good, 3.17 h)	79.1° 17:00	10.65	0%	71.4°
2038-02-05 Fri	82	—	unknown	19:20–22:25 (good, 3.08 h)	79.2° 16:55	10.62	3%	60.4°
2038-02-06 Sat	77	—	unknown	19:20–22:20 (good, 3.0 h)	79.2° 16:50	10.58	7%	49.9°
2038-02-07 Sun	70	—	unknown	19:20–22:20 (good, 3.0 h)	79.2° 16:45	10.55	13%	40.2°
2038-02-08 Mon	62	—	unknown	19:20–22:15 (good, 2.92 h)	79.2° 16:40	10.51	20%	31.9°
2038-02-09 Tue	50	—	unknown	19:25–22:00 (good, 2.58 h)	79.2° 16:40	10.47	28%	26.0°
2038-02-10 Wed	41	—	unknown	19:25–21:45 (good, 2.33 h)	79.2° 16:35	10.44	36%	24.5°
2038-02-11 Thu	31	—	unknown	19:25–20:40 (good, 1.25 h)	79.2° 16:30	10.4	46%	28.1°
2038-02-12 Fri	24	—	unknown	19:25–22:20 (marginal, 2.92 h)	79.2° 16:25	10.36	55%	35.4°
2038-02-13 Sat	20	—	unknown	19:30–22:10 (marginal, 2.67 h)	79.2° 16:20	10.32	65%	44.8°
2038-02-14 Sun	19	—	unknown	19:30–22:00 (marginal, 2.5 h)	79.2° 16:20	10.28	74%	55.5°
2038-02-15 Mon	19	—	unknown	19:30–21:55 (marginal, 2.42 h)	79.2° 16:15	10.24	83%	67.1°
2038-02-16 Tue	22	—	unknown	19:30–22:00 (marginal, 2.5 h)	79.2° 16:10	10.2	90%	79.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-01-18&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.