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: 03-21 (93), 03-22 (93), 03-23 (93), 03-24 (93), 03-25 (93) — by astronomy; check the weather when the night is within four days.

2034-03-21astronomy score per night — click a bar for that night2034-04-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-03-21 Tue	93	—	unknown	21:05–04:45 (good, 7.67 h)	50.2° 00:55	8.67	3%	163.2°
2034-03-22 Wed	93	—	unknown	21:05–04:40 (good, 7.58 h)	50.2° 00:50	8.61	9%	148.5°
2034-03-23 Thu	93	—	unknown	21:00–04:40 (good, 7.67 h)	50.2° 00:45	8.56	17%	133.8°
2034-03-24 Fri	93	—	unknown	21:00–04:35 (good, 7.58 h)	50.2° 00:40	8.51	27%	119.4°
2034-03-25 Sat	93	—	unknown	21:00–05:30 (good, 7.5 h)	50.2° 00:40	8.46	38%	105.3°
2034-03-26 Sun	92	—	unknown	22:05–05:25 (good, 7.33 h)	50.2° 01:35	8.4	49%	91.5°
2034-03-27 Mon	89	—	unknown	22:10–05:20 (good, 7.17 h)	50.2° 01:30	8.35	60%	78.1°
2034-03-28 Tue	84	—	unknown	23:50–05:20 (good, 5.5 h)	50.2° 01:25	8.3	70%	65.0°
2034-03-29 Wed	80	—	unknown	03:00–05:15 (good, 2.25 h)	50.2° 01:20	8.24	79%	52.2°
2034-03-30 Thu	49	—	unknown	21:50–05:35 (marginal, 7.75 h)	50.2° 01:20	8.19	86%	39.6°
2034-03-31 Fri	31	—	unknown	23:45–05:20 (marginal, 5.58 h)	50.2° 01:15	8.13	92%	27.3°
2034-04-01 Sat	25	—	unknown	00:55–05:05 (marginal, 4.17 h)	50.2° 01:10	8.08	97%	15.4°
2034-04-02 Sun	22	—	unknown	01:40–04:50 (marginal, 3.17 h)	50.2° 01:05	8.02	99%	5.2°
2034-04-03 Mon	24	—	unknown	21:25–04:40 (marginal, 7.25 h)	50.2° 01:05	7.97	100%	10.4°
2034-04-04 Tue	30	—	unknown	21:30–04:30 (marginal, 7.0 h)	50.2° 01:00	7.91	99%	21.8°
2034-04-05 Wed	64	—	unknown	21:30–21:35 (good, 0.08 h)	50.2° 00:55	7.86	96%	33.4°
2034-04-06 Thu	86	—	unknown	21:30–22:35 (good, 1.08 h)	50.2° 00:50	7.8	91%	45.2°
2034-04-07 Fri	91	—	unknown	21:35–01:45 (good, 4.17 h)	50.2° 00:45	7.75	85%	57.0°
2034-04-08 Sat	93	—	unknown	21:35–03:25 (good, 5.83 h)	50.2° 00:45	7.69	78%	68.8°
2034-04-09 Sun	93	—	unknown	21:35–04:05 (good, 6.5 h)	50.2° 00:40	7.63	70%	80.8°
2034-04-10 Mon	93	—	unknown	21:35–04:15 (good, 6.67 h)	50.2° 00:35	7.58	60%	93.0°
2034-04-11 Tue	93	—	unknown	21:40–04:15 (good, 6.58 h)	50.2° 00:30	7.52	50%	105.5°
2034-04-12 Wed	93	—	unknown	21:40–04:15 (good, 6.58 h)	50.2° 00:25	7.46	40%	118.3°
2034-04-13 Thu	93	—	unknown	21:40–04:15 (good, 6.58 h)	50.2° 00:25	7.4	30%	131.5°
2034-04-14 Fri	93	—	unknown	21:45–04:10 (good, 6.42 h)	50.2° 00:20	7.35	20%	145.1°
2034-04-15 Sat	93	—	unknown	21:45–04:05 (good, 6.33 h)	50.2° 00:15	7.29	12%	159.1°
2034-04-16 Sun	93	—	unknown	21:45–04:05 (good, 6.33 h)	50.2° 00:10	7.23	5%	172.7°
2034-04-17 Mon	93	—	unknown	21:50–04:00 (good, 6.17 h)	50.2° 00:10	7.17	1%	169.7°
2034-04-18 Tue	93	—	unknown	21:50–03:55 (good, 6.08 h)	50.2° 00:05	7.12	0%	155.1°
2034-04-19 Wed	93	—	unknown	21:50–03:50 (good, 6.0 h)	50.2° 00:00	7.06	2%	140.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-03-21&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.