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 HD 189733: 02-26 (20), 02-25 (19), 02-27 (19), 02-23 (18), 02-28 (18) — by astronomy; check the weather when the night is within four days.

2045-01-30astronomy score per night — click a bar for that night2045-02-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-01-30 Mon	1	—	unknown	—	71.1° 11:40	10.81	94%	128.7°
2045-01-31 Tue	1	—	unknown	—	71.1° 11:35	10.78	99%	134.2°
2045-02-01 Wed	1	—	unknown	—	71.1° 11:30	10.74	100%	136.0°
2045-02-02 Thu	1	—	unknown	—	71.1° 11:30	10.71	98%	133.7°
2045-02-03 Fri	1	—	unknown	—	71.1° 11:25	10.68	94%	128.0°
2045-02-04 Sat	2	—	unknown	05:50–05:55 (marginal, 0.08 h)	71.1° 11:20	10.64	87%	120.2°
2045-02-05 Sun	2	—	unknown	05:45–05:55 (marginal, 0.17 h)	71.1° 11:15	10.61	78%	111.3°
2045-02-06 Mon	2	—	unknown	05:45–05:55 (marginal, 0.17 h)	71.1° 11:10	10.57	69%	102.0°
2045-02-07 Tue	3	—	unknown	05:40–05:55 (marginal, 0.25 h)	71.1° 11:10	10.54	59%	92.7°
2045-02-08 Wed	3	—	unknown	05:35–05:50 (marginal, 0.25 h)	71.1° 11:05	10.5	48%	83.6°
2045-02-09 Thu	4	—	unknown	05:30–05:50 (marginal, 0.33 h)	71.1° 11:00	10.46	39%	74.9°
2045-02-10 Fri	4	—	unknown	05:30–05:50 (marginal, 0.33 h)	71.1° 10:55	10.42	30%	66.7°
2045-02-11 Sat	6	—	unknown	05:25–05:50 (marginal, 0.42 h)	71.1° 10:50	10.39	21%	59.2°
2045-02-12 Sun	7	—	unknown	05:20–06:20 (marginal, 1.0 h)	71.1° 10:50	10.35	14%	52.8°
2045-02-13 Mon	8	—	unknown	05:15–06:20 (marginal, 1.08 h)	71.1° 10:45	10.31	8%	47.8°
2045-02-14 Tue	9	—	unknown	05:40–05:45 (good, 0.08 h)	71.1° 10:40	10.27	4%	44.8°
2045-02-15 Wed	9	—	unknown	05:35–05:45 (good, 0.17 h)	71.1° 10:35	10.23	1%	44.1°
2045-02-16 Thu	11	—	unknown	05:30–05:45 (good, 0.25 h)	71.1° 10:35	10.19	0%	45.9°
2045-02-17 Fri	11	—	unknown	05:30–05:40 (good, 0.17 h)	71.1° 10:30	10.15	1%	50.1°
2045-02-18 Sat	12	—	unknown	05:25–05:40 (good, 0.25 h)	71.1° 10:25	10.11	4%	56.0°
2045-02-19 Sun	14	—	unknown	05:20–05:40 (good, 0.33 h)	71.1° 10:20	10.07	8%	63.3°
2045-02-20 Mon	15	—	unknown	05:15–05:40 (good, 0.42 h)	71.1° 10:15	10.02	14%	71.5°
2045-02-21 Tue	15	—	unknown	05:10–05:35 (good, 0.42 h)	71.1° 10:15	9.98	22%	80.4°
2045-02-22 Wed	16	—	unknown	05:10–05:35 (good, 0.42 h)	71.1° 10:10	9.94	32%	89.7°
2045-02-23 Thu	18	—	unknown	05:05–05:35 (good, 0.5 h)	71.1° 10:05	9.9	42%	99.2°
2045-02-24 Fri	17	—	unknown	05:00–05:30 (good, 0.5 h)	71.1° 10:00	9.85	53%	108.7°
2045-02-25 Sat	19	—	unknown	04:55–05:30 (good, 0.58 h)	71.1° 09:55	9.81	64%	117.8°
2045-02-26 Sun	20	—	unknown	04:50–05:30 (good, 0.67 h)	71.1° 09:55	9.76	74%	125.9°
2045-02-27 Mon	19	—	unknown	04:55–05:25 (good, 0.5 h)	71.1° 09:50	9.72	84%	132.3°
2045-02-28 Tue	18	—	unknown	04:50–05:25 (good, 0.58 h)	71.1° 09:45	9.67	92%	135.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-01-30&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.