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: 01-22 (93), 01-23 (93), 01-24 (93), 01-25 (93), 02-07 (93) — by astronomy; check the weather when the night is within four days.

2029-01-22astronomy score per night — click a bar for that night2029-02-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-01-22 Mon	93	—	unknown	01:00–06:05 (good, 5.08 h)	50.2° 04:40	11.05	51%	149.7°
2029-01-23 Tue	93	—	unknown	00:55–06:05 (good, 5.17 h)	50.2° 04:35	11.02	61%	138.2°
2029-01-24 Wed	93	—	unknown	00:55–06:05 (good, 5.17 h)	50.2° 04:35	10.99	70%	126.2°
2029-01-25 Thu	93	—	unknown	00:55–06:05 (good, 5.17 h)	50.2° 04:30	10.96	79%	113.8°
2029-01-26 Fri	92	—	unknown	01:00–06:05 (good, 5.08 h)	50.2° 04:25	10.94	87%	101.0°
2029-01-27 Sat	73	—	unknown	02:05–06:05 (good, 4.0 h)	50.2° 04:20	10.91	93%	87.7°
2029-01-28 Sun	56	—	unknown	04:00–06:05 (good, 2.08 h)	50.2° 04:15	10.88	98%	74.0°
2029-01-29 Mon	40	—	unknown	00:35–06:00 (marginal, 5.42 h)	50.2° 04:15	10.84	100%	60.1°
2029-01-30 Tue	28	—	unknown	01:10–06:00 (marginal, 4.83 h)	50.2° 04:10	10.81	99%	45.9°
2029-01-31 Wed	20	—	unknown	02:55–06:00 (marginal, 3.08 h)	50.2° 04:05	10.78	96%	31.8°
2029-02-01 Thu	23	—	unknown	00:30–06:00 (marginal, 5.5 h)	50.2° 04:00	10.75	90%	18.4°
2029-02-02 Fri	31	—	unknown	00:00–06:00 (marginal, 6.0 h)	50.2° 03:55	10.71	82%	10.0°
2029-02-03 Sat	44	—	unknown	23:45–06:00 (marginal, 6.25 h)	50.2° 03:55	10.68	72%	16.8°
2029-02-04 Sun	77	—	unknown	00:05–04:20 (good, 4.25 h)	50.2° 03:50	10.65	61%	29.5°
2029-02-05 Mon	87	—	unknown	00:00–05:55 (good, 5.92 h)	50.2° 03:45	10.61	50%	42.8°
2029-02-06 Tue	92	—	unknown	23:55–05:55 (good, 6.0 h)	50.2° 03:40	10.58	39%	56.2°
2029-02-07 Wed	93	—	unknown	23:50–05:55 (good, 6.08 h)	50.2° 03:40	10.54	28%	69.4°
2029-02-08 Thu	93	—	unknown	23:45–05:55 (good, 6.17 h)	50.2° 03:35	10.5	19%	82.5°
2029-02-09 Fri	93	—	unknown	23:45–05:50 (good, 6.08 h)	50.2° 03:30	10.47	12%	95.3°
2029-02-10 Sat	93	—	unknown	23:40–05:50 (good, 6.17 h)	50.2° 03:25	10.43	6%	107.9°
2029-02-11 Sun	93	—	unknown	23:35–05:50 (good, 6.25 h)	50.2° 03:20	10.39	2%	120.3°
2029-02-12 Mon	93	—	unknown	23:30–05:50 (good, 6.33 h)	50.2° 03:20	10.35	0%	132.4°
2029-02-13 Tue	93	—	unknown	23:25–05:45 (good, 6.33 h)	50.2° 03:15	10.31	0%	144.2°
2029-02-14 Wed	93	—	unknown	23:25–05:45 (good, 6.33 h)	50.2° 03:10	10.27	2%	155.6°
2029-02-15 Thu	93	—	unknown	23:20–05:45 (good, 6.42 h)	50.2° 03:05	10.23	6%	165.6°
2029-02-16 Fri	93	—	unknown	23:15–05:45 (good, 6.5 h)	50.2° 03:00	10.19	11%	170.0°
2029-02-17 Sat	93	—	unknown	23:10–05:40 (good, 6.5 h)	50.2° 03:00	10.15	18%	163.6°
2029-02-18 Sun	93	—	unknown	23:10–05:40 (good, 6.5 h)	50.2° 02:55	10.11	25%	153.2°
2029-02-19 Mon	93	—	unknown	23:05–05:40 (good, 6.58 h)	50.2° 02:50	10.07	34%	142.0°
2029-02-20 Tue	93	—	unknown	23:05–05:40 (good, 6.58 h)	50.2° 02:45	10.03	43%	130.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-01-22&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.