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: 02-09 (50), 02-21 (43), 02-22 (42), 02-10 (41), 02-23 (41) — by astronomy; check the weather when the night is within four days.

2038-02-09astronomy score per night — click a bar for that night2038-03-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2038-02-17 Wed	27	—	unknown	19:30–20:20 (good, 0.83 h)	79.2° 16:05	10.16	96%	92.1°
2038-02-18 Thu	32	—	unknown	19:35–21:10 (good, 1.58 h)	79.1° 16:00	10.12	99%	105.2°
2038-02-19 Fri	38	—	unknown	19:35–21:20 (good, 1.75 h)	79.2° 16:00	10.08	100%	118.4°
2038-02-20 Sat	39	—	unknown	19:35–21:15 (good, 1.67 h)	79.2° 15:55	10.04	98%	131.2°
2038-02-21 Sun	43	—	unknown	19:35–21:15 (good, 1.67 h)	79.2° 15:50	10.0	92%	143.0°
2038-02-22 Mon	42	—	unknown	19:40–21:20 (good, 1.67 h)	79.2° 15:45	9.95	85%	152.2°
2038-02-23 Tue	41	—	unknown	19:40–21:15 (good, 1.58 h)	79.2° 15:45	9.91	76%	155.6°
2038-02-24 Wed	38	—	unknown	19:40–21:10 (good, 1.5 h)	79.2° 15:40	9.87	65%	151.6°
2038-02-25 Thu	37	—	unknown	19:40–21:05 (good, 1.42 h)	79.2° 15:35	9.82	54%	142.8°
2038-02-26 Fri	34	—	unknown	19:45–21:05 (good, 1.33 h)	79.2° 15:30	9.78	43%	132.0°
2038-02-27 Sat	33	—	unknown	19:45–21:00 (good, 1.25 h)	79.2° 15:25	9.73	32%	120.6°
2038-02-28 Sun	31	—	unknown	19:45–20:55 (good, 1.17 h)	79.2° 15:25	9.69	23%	108.9°
2038-03-01 Mon	29	—	unknown	19:45–20:50 (good, 1.08 h)	79.2° 15:20	9.64	15%	97.3°
2038-03-02 Tue	28	—	unknown	19:45–20:50 (good, 1.08 h)	79.2° 15:15	9.6	9%	85.8°
2038-03-03 Wed	26	—	unknown	19:50–20:45 (good, 0.92 h)	79.2° 15:10	9.55	4%	74.5°
2038-03-04 Thu	24	—	unknown	19:50–20:40 (good, 0.83 h)	79.2° 15:05	9.5	1%	63.5°
2038-03-05 Fri	22	—	unknown	19:50–20:35 (good, 0.75 h)	79.2° 15:05	9.46	0%	52.9°
2038-03-06 Sat	21	—	unknown	19:50–20:30 (good, 0.67 h)	79.2° 15:00	9.41	1%	42.9°
2038-03-07 Sun	19	—	unknown	19:55–20:30 (good, 0.58 h)	79.2° 14:55	9.36	4%	34.1°
2038-03-08 Mon	17	—	unknown	19:55–20:20 (good, 0.42 h)	79.2° 14:50	9.32	8%	27.3°
2038-03-09 Tue	13	—	unknown	19:55–20:15 (good, 0.33 h)	79.2° 14:50	9.27	14%	24.3°
2038-03-10 Wed	11	—	unknown	19:55–20:05 (good, 0.17 h)	79.2° 14:45	9.22	21%	26.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-02-09&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.