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 Andromeda Galaxy: 02-15 (51), 02-16 (50), 02-17 (48), 02-18 (45), 02-19 (43) — by astronomy; check the weather when the night is within four days.

2028-02-15astronomy score per night — click a bar for that night2028-03-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-02-15 Tue	51	—	unknown	19:30–21:35 (good, 2.08 h)	89.7° 15:25	10.27	65%	149.8°
2028-02-16 Wed	50	—	unknown	19:30–21:30 (good, 2.0 h)	89.7° 15:20	10.23	54%	143.2°
2028-02-17 Thu	48	—	unknown	19:30–21:25 (good, 1.92 h)	89.5° 15:15	10.18	44%	134.2°
2028-02-18 Fri	45	—	unknown	19:35–21:20 (good, 1.75 h)	89.6° 15:15	10.14	34%	124.2°
2028-02-19 Sat	43	—	unknown	19:35–21:20 (good, 1.75 h)	89.7° 15:10	10.1	25%	113.8°
2028-02-20 Sun	41	—	unknown	19:35–21:15 (good, 1.67 h)	89.7° 15:05	10.06	17%	103.3°
2028-02-21 Mon	40	—	unknown	19:35–21:10 (good, 1.58 h)	89.6° 15:00	10.02	10%	92.8°
2028-02-22 Tue	38	—	unknown	19:35–21:05 (good, 1.5 h)	89.5° 14:55	9.98	6%	82.3°
2028-02-23 Wed	35	—	unknown	19:40–21:00 (good, 1.33 h)	89.6° 14:55	9.93	2%	71.9°
2028-02-24 Thu	33	—	unknown	19:40–21:00 (good, 1.33 h)	89.7° 14:50	9.89	0%	61.8°
2028-02-25 Fri	32	—	unknown	19:40–20:55 (good, 1.25 h)	89.7° 14:45	9.85	0%	52.0°
2028-02-26 Sat	31	—	unknown	19:40–20:50 (good, 1.17 h)	89.6° 14:40	9.8	2%	42.9°
2028-02-27 Sun	27	—	unknown	19:45–20:45 (good, 1.0 h)	89.5° 14:40	9.76	6%	35.1°
2028-02-28 Mon	24	—	unknown	19:45–20:40 (good, 0.92 h)	89.7° 14:35	9.71	11%	29.7°
2028-02-29 Tue	20	—	unknown	19:45–20:30 (good, 0.75 h)	89.7° 14:30	9.67	18%	28.3°
2028-03-01 Wed	17	—	unknown	19:45–20:15 (good, 0.5 h)	89.7° 14:25	9.62	26%	31.5°
2028-03-02 Thu	13	—	unknown	19:50–20:05 (good, 0.25 h)	89.5° 14:20	9.58	35%	38.5°
2028-03-03 Fri	11	—	unknown	19:50–21:00 (marginal, 1.17 h)	89.6° 14:20	9.53	45%	47.8°
2028-03-04 Sat	8	—	unknown	19:50–20:50 (marginal, 1.0 h)	89.7° 14:15	9.48	56%	58.5°
2028-03-05 Sun	7	—	unknown	19:50–20:45 (marginal, 0.92 h)	89.7° 14:10	9.44	67%	70.2°
2028-03-06 Mon	7	—	unknown	19:55–20:40 (marginal, 0.75 h)	89.6° 14:05	9.39	77%	82.6°
2028-03-07 Tue	7	—	unknown	19:55–20:40 (marginal, 0.75 h)	89.5° 14:00	9.34	86%	95.4°
2028-03-08 Wed	7	—	unknown	19:55–20:40 (marginal, 0.75 h)	89.6° 14:00	9.29	93%	108.5°
2028-03-09 Thu	7	—	unknown	19:55–20:35 (marginal, 0.67 h)	89.7° 13:55	9.25	98%	121.4°
2028-03-10 Fri	7	—	unknown	19:55–20:30 (marginal, 0.58 h)	89.7° 13:50	9.2	100%	133.6°
2028-03-11 Sat	6	—	unknown	20:00–20:30 (marginal, 0.5 h)	89.6° 13:45	9.15	99%	144.0°
2028-03-12 Sun	6	—	unknown	20:00–20:25 (marginal, 0.42 h)	89.5° 13:45	9.1	95%	150.6°
2028-03-13 Mon	5	—	unknown	20:00–20:20 (marginal, 0.33 h)	89.7° 13:40	9.05	88%	151.2°
2028-03-14 Tue	4	—	unknown	20:00–20:15 (marginal, 0.25 h)	89.7° 13:35	9.0	80%	145.9°
2028-03-15 Wed	3	—	unknown	20:05–20:15 (marginal, 0.17 h)	89.7° 13:30	8.95	70%	137.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-02-15&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.