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: 01-21 (97), 01-22 (91), 02-04 (82), 02-03 (81), 02-05 (81) — by astronomy; check the weather when the night is within four days.

2045-01-21astronomy score per night — click a bar for that night2045-02-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-01-21 Sat	97	—	unknown	19:05–23:25 (good, 4.33 h)	79.2° 17:50	11.07	12%	52.4°
2045-01-22 Sun	91	—	unknown	19:05–23:20 (good, 4.25 h)	79.2° 17:50	11.05	19%	41.1°
2045-01-23 Mon	80	—	unknown	19:05–23:15 (good, 4.17 h)	79.2° 17:45	11.02	27%	30.0°
2045-01-24 Tue	64	—	unknown	19:05–22:55 (good, 3.83 h)	79.2° 17:40	10.99	37%	20.1°
2045-01-25 Wed	48	—	unknown	19:05–22:15 (good, 3.17 h)	79.2° 17:35	10.96	47%	14.8°
2045-01-26 Thu	34	—	unknown	19:10–23:25 (marginal, 4.25 h)	79.2° 17:30	10.93	58%	19.2°
2045-01-27 Fri	23	—	unknown	19:10–23:05 (marginal, 3.92 h)	79.2° 17:30	10.9	68%	29.7°
2045-01-28 Sat	21	—	unknown	19:10–22:55 (marginal, 3.75 h)	79.2° 17:25	10.87	78%	42.5°
2045-01-29 Sun	23	—	unknown	19:10–22:50 (marginal, 3.67 h)	79.2° 17:20	10.84	87%	56.2°
2045-01-30 Mon	31	—	unknown	19:10–22:55 (marginal, 3.75 h)	79.2° 17:15	10.81	94%	70.5°
2045-01-31 Tue	41	—	unknown	19:15–20:35 (good, 1.33 h)	79.2° 17:10	10.78	99%	85.2°
2045-02-01 Wed	55	—	unknown	19:15–22:00 (good, 2.75 h)	79.2° 17:10	10.74	100%	100.0°
2045-02-02 Thu	68	—	unknown	19:15–22:20 (good, 3.08 h)	79.2° 17:05	10.71	98%	114.6°
2045-02-03 Fri	81	—	unknown	19:15–22:25 (good, 3.17 h)	79.2° 17:00	10.68	94%	128.8°
2045-02-04 Sat	82	—	unknown	19:20–22:20 (good, 3.0 h)	79.2° 16:55	10.64	87%	142.3°
2045-02-05 Sun	81	—	unknown	19:20–22:25 (good, 3.08 h)	79.2° 16:55	10.61	78%	154.5°
2045-02-06 Mon	79	—	unknown	19:20–22:20 (good, 3.0 h)	79.2° 16:50	10.57	69%	163.5°
2045-02-07 Tue	76	—	unknown	19:20–22:15 (good, 2.92 h)	79.2° 16:45	10.54	59%	164.3°
2045-02-08 Wed	74	—	unknown	19:20–22:15 (good, 2.92 h)	79.2° 16:40	10.5	48%	156.7°
2045-02-09 Thu	71	—	unknown	19:25–22:10 (good, 2.75 h)	79.2° 16:35	10.46	39%	146.3°
2045-02-10 Fri	69	—	unknown	19:25–22:05 (good, 2.67 h)	79.2° 16:35	10.42	30%	135.2°
2045-02-11 Sat	66	—	unknown	19:25–22:00 (good, 2.58 h)	79.2° 16:30	10.39	21%	123.9°
2045-02-12 Sun	64	—	unknown	19:25–22:00 (good, 2.58 h)	79.2° 16:25	10.35	14%	112.6°
2045-02-13 Mon	61	—	unknown	19:30–21:55 (good, 2.42 h)	79.2° 16:20	10.31	8%	101.2°
2045-02-14 Tue	60	—	unknown	19:30–21:50 (good, 2.33 h)	79.2° 16:15	10.27	4%	89.8°
2045-02-15 Wed	57	—	unknown	19:30–21:45 (good, 2.25 h)	79.2° 16:15	10.23	1%	78.3°
2045-02-16 Thu	55	—	unknown	19:30–21:40 (good, 2.17 h)	79.2° 16:10	10.19	0%	66.8°
2045-02-17 Fri	52	—	unknown	19:35–21:40 (good, 2.08 h)	79.2° 16:05	10.15	1%	55.2°
2045-02-18 Sat	50	—	unknown	19:35–21:35 (good, 2.0 h)	79.2° 16:00	10.11	4%	43.7°
2045-02-19 Sun	45	—	unknown	19:35–21:30 (good, 1.92 h)	79.2° 16:00	10.07	8%	32.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-01-21&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.