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: 02-22 (93), 02-23 (93), 02-24 (93), 02-25 (93), 02-26 (93) — by astronomy; check the weather when the night is within four days.

2033-02-12astronomy score per night — click a bar for that night2033-03-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2033-02-26 Sat	93	—	unknown	22:35–05:30 (good, 6.92 h)	50.2° 02:25	9.77	9%	118.2°
2033-02-27 Sun	93	—	unknown	22:30–05:30 (good, 7.0 h)	50.2° 02:20	9.72	3%	132.9°
2033-02-28 Mon	93	—	unknown	22:30–05:25 (good, 6.92 h)	50.2° 02:15	9.68	0%	147.8°
2033-03-01 Tue	93	—	unknown	22:25–05:25 (good, 7.0 h)	50.2° 02:10	9.63	1%	162.5°
2033-03-02 Wed	93	—	unknown	22:20–05:25 (good, 7.08 h)	50.2° 02:05	9.59	4%	173.7°
2033-03-03 Thu	93	—	unknown	22:15–05:20 (good, 7.08 h)	50.2° 02:05	9.54	10%	164.9°
2033-03-04 Fri	93	—	unknown	22:15–05:20 (good, 7.08 h)	50.2° 02:00	9.49	18%	150.9°
2033-03-05 Sat	93	—	unknown	22:10–05:20 (good, 7.17 h)	50.2° 01:55	9.45	28%	136.9°
2033-03-06 Sun	93	—	unknown	22:10–05:15 (good, 7.08 h)	50.2° 01:50	9.4	38%	123.2°
2033-03-07 Mon	93	—	unknown	22:10–05:15 (good, 7.08 h)	50.2° 01:50	9.35	49%	109.9°
2033-03-08 Tue	93	—	unknown	22:15–05:15 (good, 7.0 h)	50.2° 01:45	9.31	59%	97.1°
2033-03-09 Wed	91	—	unknown	22:25–05:10 (good, 6.75 h)	50.2° 01:40	9.26	69%	84.5°
2033-03-10 Thu	87	—	unknown	23:50–05:10 (good, 5.33 h)	50.2° 01:35	9.21	78%	72.2°
2033-03-11 Fri	83	—	unknown	02:05–05:10 (good, 3.08 h)	50.2° 01:30	9.16	85%	60.1°
2033-03-12 Sat	66	—	unknown	05:00–05:05 (good, 0.08 h)	50.2° 01:30	9.11	91%	48.2°
2033-03-13 Sun	34	—	unknown	23:25–05:05 (marginal, 5.67 h)	50.2° 01:25	9.06	96%	36.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-02-12&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.