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 3C 273: 03-26 (93), 03-27 (93), 03-28 (93), 03-29 (93), 03-30 (93) — by astronomy; check the weather when the night is within four days.

2046-03-26astronomy score per night — click a bar for that night2046-04-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-03-26 Mon	93	—	unknown	21:50–04:30 (good, 6.67 h)	50.1° 01:35	8.4	74%	62.8°
2046-03-27 Tue	93	—	unknown	21:45–05:00 (good, 7.25 h)	50.1° 01:30	8.35	64%	76.0°
2046-03-28 Wed	93	—	unknown	21:40–05:05 (good, 7.42 h)	50.1° 01:25	8.29	54%	88.7°
2046-03-29 Thu	93	—	unknown	21:35–05:05 (good, 7.5 h)	50.1° 01:25	8.24	44%	101.0°
2046-03-30 Fri	93	—	unknown	21:30–05:05 (good, 7.58 h)	50.1° 01:20	8.18	34%	113.1°
2046-03-31 Sat	93	—	unknown	21:30–05:05 (good, 7.58 h)	50.1° 01:15	8.13	25%	124.9°
2046-04-01 Sun	93	—	unknown	21:25–05:00 (good, 7.58 h)	50.1° 01:10	8.07	18%	136.5°
2046-04-02 Mon	93	—	unknown	21:25–05:00 (good, 7.58 h)	50.1° 01:05	8.02	11%	148.0°
2046-04-03 Tue	93	—	unknown	21:25–04:55 (good, 7.5 h)	50.1° 01:05	7.96	6%	159.0°
2046-04-04 Wed	93	—	unknown	21:30–04:50 (good, 7.33 h)	50.1° 01:00	7.91	2%	168.6°
2046-04-05 Thu	93	—	unknown	21:30–04:45 (good, 7.25 h)	50.1° 00:55	7.85	0%	170.0°
2046-04-06 Fri	93	—	unknown	21:30–04:45 (good, 7.25 h)	50.1° 00:50	7.8	0%	161.2°
2046-04-07 Sat	93	—	unknown	21:35–04:40 (good, 7.08 h)	50.1° 00:45	7.74	2%	149.9°
2046-04-08 Sun	93	—	unknown	21:35–04:35 (good, 7.0 h)	50.1° 00:45	7.68	6%	138.1°
2046-04-09 Mon	93	—	unknown	21:35–04:30 (good, 6.92 h)	50.1° 00:40	7.63	11%	125.9°
2046-04-10 Tue	93	—	unknown	21:35–04:25 (good, 6.83 h)	50.1° 00:35	7.57	18%	113.4°
2046-04-11 Wed	92	—	unknown	21:40–04:25 (good, 6.75 h)	50.1° 00:30	7.51	27%	100.6°
2046-04-12 Thu	89	—	unknown	21:40–04:20 (good, 6.67 h)	50.1° 00:30	7.46	37%	87.6°
2046-04-13 Fri	85	—	unknown	21:40–04:15 (good, 6.58 h)	50.1° 00:25	7.4	48%	74.3°
2046-04-14 Sat	81	—	unknown	22:15–04:10 (good, 5.92 h)	50.1° 00:20	7.34	59%	60.7°
2046-04-15 Sun	60	—	unknown	01:50–03:15 (good, 1.42 h)	50.1° 00:15	7.28	70%	46.8°
2046-04-16 Mon	39	—	unknown	21:45–04:25 (marginal, 6.67 h)	50.1° 00:10	7.23	80%	32.8°
2046-04-17 Tue	29	—	unknown	21:50–04:15 (marginal, 6.42 h)	50.1° 00:10	7.17	88%	19.0°
2046-04-18 Wed	24	—	unknown	21:50–04:00 (marginal, 6.17 h)	50.1° 00:05	7.11	95%	9.1°
2046-04-19 Thu	22	—	unknown	21:50–03:45 (marginal, 5.92 h)	50.1° 00:00	7.05	99%	15.7°
2046-04-20 Fri	28	—	unknown	21:50–03:35 (marginal, 5.75 h)	50.1° 23:55	6.99	100%	29.1°
2046-04-21 Sat	45	—	unknown	21:55–03:50 (marginal, 5.92 h)	50.1° 23:50	6.94	98%	43.2°
2046-04-22 Sun	92	—	unknown	21:55–00:40 (good, 2.75 h)	50.1° 23:50	6.88	94%	57.1°
2046-04-23 Mon	93	—	unknown	21:55–02:30 (good, 4.58 h)	50.1° 23:45	6.82	87%	70.7°
2046-04-24 Tue	93	—	unknown	22:00–03:10 (good, 5.17 h)	50.1° 23:40	6.76	79%	84.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-03-26&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.