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: 02-12 (93), 02-13 (93), 02-14 (93), 02-15 (93), 02-16 (93) — by astronomy; check the weather when the night is within four days.

2034-02-02astronomy score per night — click a bar for that night2034-03-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2034-02-12 Sun	93	—	unknown	23:30–05:50 (good, 6.33 h)	50.2° 03:20	10.36	36%	64.4°
2034-02-13 Mon	93	—	unknown	23:30–05:45 (good, 6.25 h)	50.2° 03:15	10.32	27%	76.7°
2034-02-14 Tue	93	—	unknown	23:25–05:45 (good, 6.33 h)	50.2° 03:10	10.28	18%	89.3°
2034-02-15 Wed	93	—	unknown	23:20–05:45 (good, 6.42 h)	50.2° 03:05	10.24	11%	102.3°
2034-02-16 Thu	93	—	unknown	23:15–05:45 (good, 6.5 h)	50.2° 03:05	10.2	5%	115.6°
2034-02-17 Fri	93	—	unknown	23:15–05:40 (good, 6.42 h)	50.2° 03:00	10.16	2%	129.3°
2034-02-18 Sat	93	—	unknown	23:10–05:40 (good, 6.5 h)	50.2° 02:55	10.12	0%	143.4°
2034-02-19 Sun	93	—	unknown	23:05–05:40 (good, 6.58 h)	50.2° 02:50	10.08	1%	157.6°
2034-02-20 Mon	93	—	unknown	23:00–05:40 (good, 6.67 h)	50.2° 02:50	10.04	5%	171.3°
2034-02-21 Tue	93	—	unknown	22:55–05:35 (good, 6.67 h)	50.2° 02:45	10.0	12%	171.5°
2034-02-22 Wed	93	—	unknown	22:55–05:35 (good, 6.67 h)	50.2° 02:40	9.95	20%	157.8°
2034-02-23 Thu	93	—	unknown	22:50–05:35 (good, 6.75 h)	50.2° 02:35	9.91	30%	143.6°
2034-02-24 Fri	93	—	unknown	22:50–05:30 (good, 6.67 h)	50.2° 02:30	9.87	42%	129.5°
2034-02-25 Sat	93	—	unknown	22:50–05:30 (good, 6.67 h)	50.2° 02:30	9.82	53%	115.5°
2034-02-26 Sun	93	—	unknown	22:55–05:30 (good, 6.58 h)	50.2° 02:25	9.78	64%	101.8°
2034-02-27 Mon	91	—	unknown	23:00–05:30 (good, 6.5 h)	50.2° 02:20	9.73	74%	88.3°
2034-02-28 Tue	88	—	unknown	00:35–05:25 (good, 4.83 h)	50.2° 02:15	9.69	83%	75.0°
2034-03-01 Wed	83	—	unknown	03:05–05:25 (good, 2.33 h)	50.2° 02:10	9.64	90%	61.9°
2034-03-02 Thu	45	—	unknown	22:40–05:25 (marginal, 6.75 h)	50.2° 02:10	9.6	95%	49.1°
2034-03-03 Fri	30	—	unknown	00:50–05:20 (marginal, 4.5 h)	50.2° 02:05	9.55	99%	36.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-02-02&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.