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: 02-20 (47), 02-21 (46), 02-22 (43), 02-23 (41), 02-24 (39) — by astronomy; check the weather when the night is within four days.

2047-02-20astronomy score per night — click a bar for that night2047-03-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-02-20 Wed	47	—	unknown	19:35–21:30 (good, 1.92 h)	79.2° 15:55	10.04	14%	104.9°
2047-02-21 Thu	46	—	unknown	19:35–21:25 (good, 1.83 h)	79.2° 15:50	10.0	8%	92.3°
2047-02-22 Fri	43	—	unknown	19:40–21:20 (good, 1.67 h)	79.2° 15:50	9.96	3%	80.0°
2047-02-23 Sat	41	—	unknown	19:40–21:15 (good, 1.58 h)	79.2° 15:45	9.92	1%	67.8°
2047-02-24 Sun	39	—	unknown	19:40–21:15 (good, 1.58 h)	79.2° 15:40	9.87	0%	56.0°
2047-02-25 Mon	38	—	unknown	19:40–21:10 (good, 1.5 h)	79.2° 15:35	9.83	1%	44.4°
2047-02-26 Tue	35	—	unknown	19:40–21:05 (good, 1.42 h)	79.2° 15:30	9.79	4%	33.4°
2047-02-27 Wed	31	—	unknown	19:45–21:00 (good, 1.25 h)	79.2° 15:30	9.74	9%	23.3°
2047-02-28 Thu	26	—	unknown	19:45–20:50 (good, 1.08 h)	79.2° 15:25	9.7	15%	15.8°
2047-03-01 Fri	22	—	unknown	19:45–20:40 (good, 0.92 h)	79.2° 15:20	9.65	23%	15.2°
2047-03-02 Sat	18	—	unknown	19:45–20:30 (good, 0.75 h)	79.2° 15:15	9.61	31%	22.0°
2047-03-03 Sun	13	—	unknown	19:50–21:15 (marginal, 1.42 h)	79.2° 15:15	9.56	40%	31.9°
2047-03-04 Mon	11	—	unknown	19:50–21:05 (marginal, 1.25 h)	79.2° 15:10	9.51	50%	43.0°
2047-03-05 Tue	9	—	unknown	19:50–20:55 (marginal, 1.08 h)	79.2° 15:05	9.47	60%	54.7°
2047-03-06 Wed	9	—	unknown	19:50–20:50 (marginal, 1.0 h)	79.2° 15:00	9.42	70%	67.0°
2047-03-07 Thu	9	—	unknown	19:55–20:50 (marginal, 0.92 h)	79.2° 14:55	9.37	79%	79.7°
2047-03-08 Fri	9	—	unknown	19:55–20:50 (marginal, 0.92 h)	79.2° 14:55	9.32	87%	92.9°
2047-03-09 Sat	10	—	unknown	19:55–20:00 (good, 0.08 h)	79.2° 14:50	9.28	94%	106.6°
2047-03-10 Sun	11	—	unknown	19:55–20:05 (good, 0.17 h)	79.2° 14:45	9.23	98%	120.6°
2047-03-11 Mon	9	—	unknown	20:00–20:05 (good, 0.08 h)	79.2° 14:40	9.18	100%	134.7°
2047-03-12 Tue	9	—	unknown	19:25–20:40 (marginal, 1.25 h)	79.2° 14:35	9.13	99%	148.5°
2047-03-13 Wed	9	—	unknown	20:00–20:05 (good, 0.08 h)	79.2° 14:35	9.08	95%	160.5°
2047-03-14 Thu	8	—	unknown	19:30–20:30 (marginal, 1.0 h)	79.2° 14:30	9.03	88%	165.5°
2047-03-15 Fri	6	—	unknown	19:30–20:00 (marginal, 0.5 h)	79.2° 14:25	8.98	79%	158.3°
2047-03-16 Sat	5	—	unknown	20:05–20:25 (marginal, 0.33 h)	79.2° 14:20	8.93	69%	146.3°
2047-03-17 Sun	4	—	unknown	19:30–19:50 (marginal, 0.33 h)	79.2° 14:20	8.88	58%	133.4°
2047-03-18 Mon	3	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:15	8.83	47%	120.5°
2047-03-19 Tue	2	—	unknown	19:35–19:40 (marginal, 0.08 h)	79.2° 14:10	8.78	37%	107.7°
2047-03-20 Wed	1	—	unknown	19:35–19:40 (marginal, 0.08 h)	79.2° 14:05	8.73	27%	95.2°
2047-03-21 Thu	1	—	unknown	—	79.2° 14:00	8.67	18%	82.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-02-20&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.