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: 01-04 (93), 01-05 (93), 01-06 (93), 01-07 (93), 01-08 (93) — by astronomy; check the weather when the night is within four days.

2033-01-04astronomy score per night — click a bar for that night2033-02-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-01-04 Tue	93	—	unknown	02:05–06:10 (good, 4.08 h)	50.2° 05:50	11.41	16%	145.3°
2033-01-05 Wed	93	—	unknown	02:00–06:10 (good, 4.17 h)	50.2° 05:50	11.4	26%	159.3°
2033-01-06 Thu	93	—	unknown	01:55–06:10 (good, 4.25 h)	50.2° 05:45	11.38	36%	171.6°
2033-01-07 Fri	93	—	unknown	01:55–06:10 (good, 4.25 h)	50.2° 05:40	11.37	48%	169.0°
2033-01-08 Sat	93	—	unknown	01:50–06:10 (good, 4.33 h)	50.2° 05:35	11.35	59%	156.4°
2033-01-09 Sun	93	—	unknown	01:50–06:10 (good, 4.33 h)	50.2° 05:30	11.34	69%	143.1°
2033-01-10 Mon	93	—	unknown	01:50–06:10 (good, 4.33 h)	50.2° 05:30	11.32	79%	129.8°
2033-01-11 Tue	93	—	unknown	01:50–06:10 (good, 4.33 h)	50.2° 05:25	11.3	87%	116.7°
2033-01-12 Wed	92	—	unknown	01:55–06:10 (good, 4.25 h)	50.2° 05:20	11.28	93%	103.7°
2033-01-13 Thu	66	—	unknown	02:45–06:10 (good, 3.42 h)	50.2° 05:15	11.26	97%	90.9°
2033-01-14 Fri	52	—	unknown	04:10–06:10 (good, 2.0 h)	50.2° 05:10	11.24	99%	78.3°
2033-01-15 Sat	40	—	unknown	01:25–06:10 (marginal, 4.75 h)	50.2° 05:10	11.22	100%	66.0°
2033-01-16 Sun	30	—	unknown	01:35–06:10 (marginal, 4.58 h)	50.2° 05:05	11.2	98%	53.8°
2033-01-17 Mon	23	—	unknown	01:40–06:10 (marginal, 4.5 h)	50.2° 05:00	11.17	94%	41.8°
2033-01-18 Tue	19	—	unknown	01:45–06:10 (marginal, 4.42 h)	50.2° 04:55	11.15	89%	30.1°
2033-01-19 Wed	23	—	unknown	01:10–06:10 (marginal, 5.0 h)	50.2° 04:55	11.12	83%	18.7°
2033-01-20 Thu	30	—	unknown	00:50–06:10 (marginal, 5.33 h)	50.2° 04:50	11.1	75%	8.6°
2033-01-21 Fri	39	—	unknown	00:35–06:05 (marginal, 5.5 h)	50.2° 04:45	11.07	67%	8.9°
2033-01-22 Sat	52	—	unknown	03:00–04:05 (good, 1.08 h)	50.2° 04:40	11.05	58%	19.1°
2033-01-23 Sun	79	—	unknown	00:50–06:05 (good, 5.25 h)	50.2° 04:35	11.02	48%	30.8°
2033-01-24 Mon	86	—	unknown	00:45–06:05 (good, 5.33 h)	50.2° 04:35	10.99	38%	42.9°
2033-01-25 Tue	91	—	unknown	00:40–06:05 (good, 5.42 h)	50.2° 04:30	10.96	29%	55.5°
2033-01-26 Wed	93	—	unknown	00:40–06:05 (good, 5.42 h)	50.2° 04:25	10.93	20%	68.5°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-01-04&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.