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: 03-18 (93), 03-19 (93), 03-20 (93), 03-21 (93), 03-22 (93) — by astronomy; check the weather when the night is within four days.

2036-03-17astronomy score per night — click a bar for that night2036-04-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-03-17 Mon	92	—	unknown	21:20–03:50 (good, 6.5 h)	50.2° 01:10	8.85	68%	61.2°
2036-03-18 Tue	93	—	unknown	21:15–04:35 (good, 7.33 h)	50.2° 01:05	8.8	58%	73.4°
2036-03-19 Wed	93	—	unknown	21:15–04:40 (good, 7.42 h)	50.2° 01:00	8.74	48%	85.4°
2036-03-20 Thu	93	—	unknown	21:10–04:40 (good, 7.5 h)	50.2° 00:55	8.69	39%	97.3°
2036-03-21 Fri	93	—	unknown	21:05–04:40 (good, 7.58 h)	50.2° 00:50	8.64	30%	109.1°
2036-03-22 Sat	93	—	unknown	21:00–04:40 (good, 7.67 h)	50.2° 00:50	8.59	22%	121.0°
2036-03-23 Sun	93	—	unknown	20:55–04:35 (good, 7.67 h)	50.2° 00:45	8.54	14%	132.9°
2036-03-24 Mon	93	—	unknown	20:55–04:30 (good, 7.58 h)	50.2° 00:40	8.48	8%	145.0°
2036-03-25 Tue	93	—	unknown	20:50–04:30 (good, 7.67 h)	50.2° 00:35	8.43	4%	157.3°
2036-03-26 Wed	93	—	unknown	20:45–04:25 (good, 7.67 h)	50.2° 00:30	8.38	1%	169.7°
2036-03-27 Thu	93	—	unknown	20:40–04:20 (good, 7.67 h)	50.2° 00:30	8.32	0%	177.1°
2036-03-28 Fri	93	—	unknown	20:40–04:15 (good, 7.58 h)	50.2° 00:25	8.27	1%	164.4°
2036-03-29 Sat	93	—	unknown	20:35–05:10 (good, 7.58 h)	50.2° 00:20	8.21	5%	151.2°
2036-03-30 Sun	93	—	unknown	21:30–05:10 (good, 7.67 h)	50.2° 01:15	8.16	10%	137.7°
2036-03-31 Mon	93	—	unknown	21:25–05:05 (good, 7.67 h)	50.2° 01:15	8.11	18%	124.1°
2036-04-01 Tue	93	—	unknown	21:25–05:00 (good, 7.58 h)	50.2° 01:10	8.05	27%	110.3°
2036-04-02 Wed	93	—	unknown	21:30–04:55 (good, 7.42 h)	50.2° 01:05	8.0	38%	96.4°
2036-04-03 Thu	90	—	unknown	21:35–04:55 (good, 7.33 h)	50.2° 01:00	7.94	49%	82.4°
2036-04-04 Fri	84	—	unknown	22:25–04:50 (good, 6.42 h)	50.2° 00:55	7.88	61%	68.2°
2036-04-05 Sat	75	—	unknown	01:00–04:45 (good, 3.75 h)	50.2° 00:55	7.83	72%	54.0°
2036-04-06 Sun	47	—	unknown	21:30–05:10 (marginal, 7.67 h)	50.2° 00:50	7.77	81%	39.7°
2036-04-07 Mon	29	—	unknown	22:45–04:50 (marginal, 6.08 h)	50.2° 00:45	7.72	89%	25.4°
2036-04-08 Tue	22	—	unknown	00:35–04:30 (marginal, 3.92 h)	50.2° 00:40	7.66	95%	11.3°
2036-04-09 Wed	19	—	unknown	02:05–04:15 (marginal, 2.17 h)	50.2° 00:35	7.6	99%	3.2°
2036-04-10 Thu	23	—	unknown	21:40–02:05 (marginal, 4.42 h)	50.2° 00:35	7.55	100%	16.8°
2036-04-11 Fri	31	—	unknown	21:40–03:55 (marginal, 6.25 h)	50.2° 00:30	7.49	98%	30.3°
2036-04-12 Sat	76	—	unknown	21:40–21:55 (good, 0.25 h)	50.2° 00:25	7.43	95%	43.5°
2036-04-13 Sun	90	—	unknown	21:40–00:50 (good, 3.17 h)	50.2° 00:20	7.38	89%	56.4°
2036-04-14 Mon	93	—	unknown	21:45–02:45 (good, 5.0 h)	50.2° 00:20	7.32	82%	68.9°
2036-04-15 Tue	93	—	unknown	21:45–03:40 (good, 5.92 h)	50.2° 00:15	7.26	74%	81.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-03-17&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.