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: 02-15 (93), 02-16 (93), 02-17 (93), 02-18 (93), 02-19 (93) — by astronomy; check the weather when the night is within four days.

2034-02-15astronomy score per night — click a bar for that night2034-03-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2034-03-04 Sat	22	—	unknown	02:25–05:20 (marginal, 2.92 h)	50.2° 02:00	9.51	100%	24.1°
2034-03-05 Sun	22	—	unknown	02:30–05:20 (marginal, 2.83 h)	50.2° 01:55	9.46	99%	12.2°
2034-03-06 Mon	23	—	unknown	22:15–05:15 (marginal, 7.0 h)	50.2° 01:55	9.41	97%	4.6°
2034-03-07 Tue	30	—	unknown	21:55–05:15 (marginal, 7.33 h)	50.2° 01:50	9.36	93%	13.6°
2034-03-08 Wed	45	—	unknown	21:30–05:15 (marginal, 7.75 h)	50.2° 01:45	9.32	87%	25.1°
2034-03-09 Thu	82	—	unknown	21:55–22:45 (good, 0.83 h)	50.2° 01:40	9.27	80%	36.8°
2034-03-10 Fri	88	—	unknown	21:50–02:45 (good, 4.92 h)	50.2° 01:35	9.22	72%	48.6°
2034-03-11 Sat	92	—	unknown	21:45–04:35 (good, 6.83 h)	50.2° 01:35	9.17	63%	60.4°
2034-03-12 Sun	93	—	unknown	21:40–05:00 (good, 7.33 h)	50.2° 01:30	9.12	53%	72.4°
2034-03-13 Mon	93	—	unknown	21:40–05:05 (good, 7.42 h)	50.2° 01:25	9.07	44%	84.6°
2034-03-14 Tue	93	—	unknown	21:35–05:05 (good, 7.5 h)	50.2° 01:20	9.02	34%	97.1°
2034-03-15 Wed	93	—	unknown	21:30–05:00 (good, 7.5 h)	50.2° 01:15	8.97	24%	110.0°
2034-03-16 Thu	93	—	unknown	21:25–05:00 (good, 7.58 h)	50.2° 01:15	8.92	16%	123.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-02-15&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.