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: 02-27 (21), 02-28 (21), 02-26 (19), 02-25 (17), 02-24 (14) — by astronomy; check the weather when the night is within four days.

2033-01-30astronomy score per night — click a bar for that night2033-02-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-01-30 Sun	1	—	unknown	—	71.1° 11:40	10.81	0%	37.5°
2033-01-31 Mon	1	—	unknown	—	71.1° 11:35	10.78	2%	41.2°
2033-02-01 Tue	1	—	unknown	—	71.1° 11:30	10.75	6%	48.7°
2033-02-02 Wed	1	—	unknown	06:25–06:30 (marginal, 0.08 h)	71.1° 11:30	10.71	13%	58.4°
2033-02-03 Thu	2	—	unknown	05:55–06:00 (marginal, 0.08 h)	71.1° 11:25	10.68	22%	69.2°
2033-02-04 Fri	3	—	unknown	06:20–06:30 (marginal, 0.17 h)	71.1° 11:20	10.65	32%	80.4°
2033-02-05 Sat	3	—	unknown	06:15–06:30 (marginal, 0.25 h)	71.1° 11:15	10.61	43%	91.5°
2033-02-06 Sun	3	—	unknown	06:10–06:25 (marginal, 0.25 h)	71.1° 11:10	10.58	54%	102.3°
2033-02-07 Mon	4	—	unknown	05:40–05:55 (marginal, 0.25 h)	71.1° 11:10	10.54	65%	112.6°
2033-02-08 Tue	5	—	unknown	05:35–05:55 (marginal, 0.33 h)	71.1° 11:05	10.5	74%	122.1°
2033-02-09 Wed	5	—	unknown	05:30–05:50 (marginal, 0.33 h)	71.1° 11:00	10.47	82%	130.5°
2033-02-10 Thu	6	—	unknown	05:55–06:25 (marginal, 0.5 h)	71.1° 10:55	10.43	89%	137.2°
2033-02-11 Fri	6	—	unknown	05:25–06:20 (marginal, 0.92 h)	71.1° 10:50	10.39	95%	141.5°
2033-02-12 Sat	6	—	unknown	05:20–05:50 (marginal, 0.5 h)	71.1° 10:50	10.35	98%	142.7°
2033-02-13 Sun	6	—	unknown	05:15–05:45 (marginal, 0.5 h)	71.1° 10:45	10.31	100%	140.6°
2033-02-14 Mon	7	—	unknown	05:10–05:45 (marginal, 0.58 h)	71.1° 10:40	10.27	100%	135.7°
2033-02-15 Tue	8	—	unknown	05:10–06:15 (marginal, 1.08 h)	71.1° 10:35	10.23	98%	129.0°
2033-02-16 Wed	9	—	unknown	05:40–05:45 (good, 0.08 h)	71.1° 10:35	10.19	94%	121.0°
2033-02-17 Thu	8	—	unknown	05:00–06:15 (marginal, 1.25 h)	71.1° 10:30	10.15	88%	112.3°
2033-02-18 Fri	9	—	unknown	04:55–06:15 (marginal, 1.33 h)	71.1° 10:25	10.11	82%	103.2°
2033-02-19 Sat	9	—	unknown	04:50–06:10 (marginal, 1.33 h)	71.1° 10:20	10.07	74%	93.7°
2033-02-20 Sun	9	—	unknown	05:35–05:40 (good, 0.08 h)	71.1° 10:15	10.03	65%	84.1°
2033-02-21 Mon	10	—	unknown	05:30–05:35 (good, 0.08 h)	71.1° 10:15	9.99	56%	74.4°
2033-02-22 Tue	11	—	unknown	05:25–05:35 (good, 0.17 h)	71.1° 10:10	9.94	46%	64.8°
2033-02-23 Wed	13	—	unknown	05:20–05:35 (good, 0.25 h)	71.1° 10:05	9.9	35%	55.5°
2033-02-24 Thu	14	—	unknown	05:10–05:30 (good, 0.33 h)	71.1° 10:00	9.86	25%	47.0°
2033-02-25 Fri	17	—	unknown	05:00–05:30 (good, 0.5 h)	71.1° 09:55	9.81	16%	40.5°
2033-02-26 Sat	19	—	unknown	04:50–05:30 (good, 0.67 h)	71.1° 09:55	9.77	9%	37.3°
2033-02-27 Sun	21	—	unknown	04:50–05:30 (good, 0.67 h)	71.1° 09:50	9.72	3%	38.9°
2033-02-28 Mon	21	—	unknown	04:45–05:25 (good, 0.67 h)	71.1° 09:45	9.68	0%	44.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-01-30&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.