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: 01-16 (93), 01-17 (93), 01-18 (93), 01-19 (93), 01-20 (93) — by astronomy; check the weather when the night is within four days.

2034-01-13astronomy score per night — click a bar for that night2034-02-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-01-13 Fri	79	—	unknown	01:30–06:10 (good, 4.67 h)	50.2° 05:15	11.27	37%	32.9°
2034-01-14 Sat	87	—	unknown	01:25–06:10 (good, 4.75 h)	50.2° 05:15	11.24	28%	44.7°
2034-01-15 Sun	91	—	unknown	01:20–06:10 (good, 4.83 h)	50.2° 05:10	11.22	20%	56.7°
2034-01-16 Mon	93	—	unknown	01:20–06:10 (good, 4.83 h)	50.2° 05:05	11.2	13%	69.0°
2034-01-17 Tue	93	—	unknown	01:15–06:10 (good, 4.92 h)	50.2° 05:00	11.18	7%	81.5°
2034-01-18 Wed	93	—	unknown	01:10–06:10 (good, 5.0 h)	50.2° 05:00	11.16	3%	94.4°
2034-01-19 Thu	93	—	unknown	01:05–06:10 (good, 5.08 h)	50.2° 04:55	11.13	0%	107.5°
2034-01-20 Fri	93	—	unknown	01:05–06:10 (good, 5.08 h)	50.2° 04:50	11.11	0%	121.0°
2034-01-21 Sat	93	—	unknown	01:00–06:05 (good, 5.08 h)	50.2° 04:45	11.08	3%	134.7°
2034-01-22 Sun	93	—	unknown	00:55–06:05 (good, 5.17 h)	50.2° 04:40	11.05	8%	148.5°
2034-01-23 Mon	93	—	unknown	00:50–06:05 (good, 5.25 h)	50.2° 04:40	11.03	15%	162.3°
2034-01-24 Tue	93	—	unknown	00:45–06:05 (good, 5.33 h)	50.2° 04:35	11.0	24%	174.5°
2034-01-25 Wed	93	—	unknown	00:45–06:05 (good, 5.33 h)	50.2° 04:30	10.97	34%	167.9°
2034-01-26 Thu	93	—	unknown	00:40–06:05 (good, 5.42 h)	50.2° 04:25	10.94	45%	154.2°
2034-01-27 Fri	93	—	unknown	00:40–06:05 (good, 5.42 h)	50.2° 04:20	10.91	57%	140.3°
2034-01-28 Sat	93	—	unknown	00:40–06:05 (good, 5.42 h)	50.2° 04:20	10.88	68%	126.3°
2034-01-29 Sun	93	—	unknown	00:40–06:00 (good, 5.33 h)	50.2° 04:15	10.85	78%	112.4°
2034-01-30 Mon	93	—	unknown	00:50–06:00 (good, 5.17 h)	50.2° 04:10	10.82	86%	98.6°
2034-01-31 Tue	90	—	unknown	02:00–06:00 (good, 4.0 h)	50.2° 04:05	10.79	93%	84.9°
2034-02-01 Wed	57	—	unknown	03:55–06:00 (good, 2.08 h)	50.2° 04:05	10.76	97%	71.5°
2034-02-02 Thu	41	—	unknown	00:25–06:00 (marginal, 5.58 h)	50.2° 04:00	10.72	100%	58.2°
2034-02-03 Fri	29	—	unknown	01:05–06:00 (marginal, 4.92 h)	50.2° 03:55	10.69	100%	45.2°
2034-02-04 Sat	20	—	unknown	03:10–05:55 (marginal, 2.75 h)	50.2° 03:50	10.65	98%	32.5°
2034-02-05 Sun	20	—	unknown	02:10–05:55 (marginal, 3.75 h)	50.2° 03:45	10.62	94%	20.1°
2034-02-06 Mon	24	—	unknown	00:00–05:55 (marginal, 5.92 h)	50.2° 03:45	10.58	88%	8.6°
2034-02-07 Tue	31	—	unknown	23:40–05:55 (marginal, 6.25 h)	50.2° 03:40	10.55	81%	6.6°
2034-02-08 Wed	43	—	unknown	23:25–05:55 (marginal, 6.5 h)	50.2° 03:35	10.51	73%	17.3°
2034-02-09 Thu	68	—	unknown	23:45–00:00 (good, 0.25 h)	50.2° 03:30	10.47	64%	28.9°
2034-02-10 Fri	85	—	unknown	23:40–05:45 (good, 6.08 h)	50.2° 03:25	10.44	55%	40.6°
2034-02-11 Sat	90	—	unknown	23:35–05:50 (good, 6.25 h)	50.2° 03:25	10.4	46%	52.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-01-13&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.