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: 02-05 (93), 02-06 (93), 02-07 (93), 02-08 (93), 02-09 (93) — by astronomy; check the weather when the night is within four days.

2038-02-05astronomy score per night — click a bar for that night2038-03-06

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-02-05 Fri	93	—	unknown	00:00–05:55 (good, 5.92 h)	50.1° 03:45	10.62	3%	150.7°
2038-02-06 Sat	93	—	unknown	23:55–05:55 (good, 6.0 h)	50.1° 03:45	10.58	7%	162.8°
2038-02-07 Sun	93	—	unknown	23:50–05:55 (good, 6.08 h)	50.1° 03:40	10.55	13%	174.8°
2038-02-08 Mon	93	—	unknown	23:50–05:55 (good, 6.08 h)	50.1° 03:35	10.51	20%	173.3°
2038-02-09 Tue	93	—	unknown	23:45–05:50 (good, 6.08 h)	50.1° 03:30	10.47	28%	161.5°
2038-02-10 Wed	93	—	unknown	23:45–05:50 (good, 6.08 h)	50.1° 03:25	10.44	36%	149.7°
2038-02-11 Thu	93	—	unknown	23:40–05:50 (good, 6.17 h)	50.1° 03:25	10.4	46%	137.8°
2038-02-12 Fri	93	—	unknown	23:40–05:50 (good, 6.17 h)	50.1° 03:20	10.36	55%	125.7°
2038-02-13 Sat	93	—	unknown	23:40–05:45 (good, 6.08 h)	50.1° 03:15	10.32	65%	113.3°
2038-02-14 Sun	93	—	unknown	23:45–05:45 (good, 6.0 h)	50.1° 03:10	10.28	74%	100.6°
2038-02-15 Mon	90	—	unknown	00:20–05:45 (good, 5.42 h)	50.1° 03:10	10.24	83%	87.5°
2038-02-16 Tue	85	—	unknown	02:15–05:45 (good, 3.5 h)	50.1° 03:05	10.2	90%	73.9°
2038-02-17 Wed	49	—	unknown	23:20–05:40 (marginal, 6.33 h)	50.1° 03:00	10.16	96%	59.9°
2038-02-18 Thu	31	—	unknown	00:35–05:40 (marginal, 5.08 h)	50.1° 02:55	10.12	99%	45.4°
2038-02-19 Fri	18	—	unknown	03:40–05:40 (marginal, 2.0 h)	50.1° 02:50	10.08	100%	30.7°
2038-02-20 Sat	18	—	unknown	03:50–05:40 (marginal, 1.83 h)	50.1° 02:50	10.04	98%	15.8°
2038-02-21 Sun	21	—	unknown	23:05–05:35 (marginal, 6.5 h)	50.1° 02:45	10.0	92%	0.9°
2038-02-22 Mon	33	—	unknown	22:40–05:35 (marginal, 6.92 h)	50.1° 02:40	9.95	85%	13.9°
2038-02-23 Tue	58	—	unknown	22:50–22:55 (good, 0.08 h)	50.1° 02:35	9.91	76%	28.6°
2038-02-24 Wed	85	—	unknown	22:45–03:45 (good, 5.0 h)	50.1° 02:30	9.87	65%	42.9°
2038-02-25 Thu	91	—	unknown	22:40–05:30 (good, 6.83 h)	50.1° 02:30	9.82	54%	56.9°
2038-02-26 Fri	93	—	unknown	22:40–05:30 (good, 6.83 h)	50.1° 02:25	9.78	43%	70.6°
2038-02-27 Sat	93	—	unknown	22:35–05:30 (good, 6.92 h)	50.1° 02:20	9.73	32%	83.9°
2038-02-28 Sun	93	—	unknown	22:30–05:25 (good, 6.92 h)	50.1° 02:15	9.69	23%	97.0°
2038-03-01 Mon	93	—	unknown	22:25–05:25 (good, 7.0 h)	50.1° 02:15	9.64	15%	109.8°
2038-03-02 Tue	93	—	unknown	22:20–05:25 (good, 7.08 h)	50.1° 02:10	9.6	9%	122.5°
2038-03-03 Wed	93	—	unknown	22:20–05:20 (good, 7.0 h)	50.1° 02:05	9.55	4%	134.9°
2038-03-04 Thu	93	—	unknown	22:15–05:20 (good, 7.08 h)	50.1° 02:00	9.5	1%	147.2°
2038-03-05 Fri	93	—	unknown	22:10–05:20 (good, 7.17 h)	50.1° 01:55	9.46	0%	159.3°
2038-03-06 Sat	93	—	unknown	22:05–05:15 (good, 7.17 h)	50.1° 01:55	9.41	1%	171.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-02-05&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.