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: 01-27 (93), 01-28 (93), 01-29 (93), 01-30 (93), 01-31 (93) — by astronomy; check the weather when the night is within four days.

2033-01-27astronomy score per night — click a bar for that night2033-02-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-01-27 Thu	93	—	unknown	00:35–06:05 (good, 5.5 h)	50.2° 04:20	10.91	12%	82.0°
2033-01-28 Fri	93	—	unknown	00:30–06:05 (good, 5.58 h)	50.2° 04:15	10.87	6%	96.0°
2033-01-29 Sat	93	—	unknown	00:25–06:00 (good, 5.58 h)	50.2° 04:15	10.84	2%	110.4°
2033-01-30 Sun	93	—	unknown	00:20–06:00 (good, 5.67 h)	50.2° 04:10	10.81	0%	125.0°
2033-01-31 Mon	93	—	unknown	00:20–06:00 (good, 5.67 h)	50.2° 04:05	10.78	2%	139.8°
2033-02-01 Tue	93	—	unknown	00:15–06:00 (good, 5.75 h)	50.2° 04:00	10.75	6%	154.5°
2033-02-02 Wed	93	—	unknown	00:10–06:00 (good, 5.83 h)	50.2° 04:00	10.71	13%	168.3°
2033-02-03 Thu	93	—	unknown	00:05–06:00 (good, 5.92 h)	50.2° 03:55	10.68	22%	172.0°
2033-02-04 Fri	93	—	unknown	00:05–05:55 (good, 5.83 h)	50.2° 03:50	10.65	32%	159.8°
2033-02-05 Sat	93	—	unknown	00:00–05:55 (good, 5.92 h)	50.2° 03:45	10.61	43%	146.2°
2033-02-06 Sun	93	—	unknown	00:00–05:55 (good, 5.92 h)	50.2° 03:40	10.58	54%	132.8°
2033-02-07 Mon	93	—	unknown	00:00–05:55 (good, 5.92 h)	50.2° 03:40	10.54	65%	119.6°
2033-02-08 Tue	93	—	unknown	00:05–05:55 (good, 5.83 h)	50.2° 03:35	10.5	74%	106.7°
2033-02-09 Wed	92	—	unknown	00:10–05:50 (good, 5.67 h)	50.2° 03:30	10.47	82%	94.0°
2033-02-10 Thu	89	—	unknown	01:30–05:50 (good, 4.33 h)	50.2° 03:25	10.43	89%	81.5°
2033-02-11 Fri	63	—	unknown	03:20–05:50 (good, 2.5 h)	50.2° 03:20	10.39	95%	69.2°
2033-02-12 Sat	46	—	unknown	23:45–05:50 (marginal, 6.08 h)	50.2° 03:20	10.35	98%	57.1°
2033-02-13 Sun	33	—	unknown	00:25–05:45 (marginal, 5.33 h)	50.2° 03:15	10.31	100%	45.1°
2033-02-14 Mon	23	—	unknown	02:35–05:45 (marginal, 3.17 h)	50.2° 03:10	10.27	100%	33.3°
2033-02-15 Tue	21	—	unknown	02:50–05:45 (marginal, 2.92 h)	50.2° 03:05	10.23	98%	21.8°
2033-02-16 Wed	23	—	unknown	23:30–05:45 (marginal, 6.25 h)	50.2° 03:05	10.19	94%	11.0°
2033-02-17 Thu	27	—	unknown	23:05–05:40 (marginal, 6.58 h)	50.2° 03:00	10.15	88%	6.8°
2033-02-18 Fri	38	—	unknown	22:50–05:40 (marginal, 6.83 h)	50.2° 02:55	10.11	82%	15.8°
2033-02-19 Sat	59	—	unknown	23:05–23:10 (good, 0.08 h)	50.2° 02:50	10.07	74%	27.2°
2033-02-20 Sun	84	—	unknown	23:00–03:35 (good, 4.58 h)	50.2° 02:45	10.03	65%	39.1°
2033-02-21 Mon	89	—	unknown	22:55–05:35 (good, 6.67 h)	50.2° 02:45	9.99	56%	51.2°
2033-02-22 Tue	93	—	unknown	22:50–05:35 (good, 6.75 h)	50.2° 02:40	9.94	46%	63.7°
2033-02-23 Wed	93	—	unknown	22:50–05:35 (good, 6.75 h)	50.2° 02:35	9.9	35%	76.7°
2033-02-24 Thu	93	—	unknown	22:45–05:30 (good, 6.75 h)	50.2° 02:30	9.86	25%	90.1°
2033-02-25 Fri	93	—	unknown	22:40–05:30 (good, 6.83 h)	50.2° 02:25	9.81	16%	103.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-01-27&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.