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: 06-02 (21), 06-01 (19), 05-31 (18), 05-30 (17), 05-29 (16) — by astronomy; check the weather when the night is within four days.

2033-05-04astronomy score per night — click a bar for that night2033-06-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-05-04 Wed	1	—	unknown	—	89.6° 11:10	6.17	37%	94.0°
2033-05-05 Thu	2	—	unknown	—	89.5° 11:10	6.12	46%	104.3°
2033-05-06 Fri	2	—	unknown	05:00–05:05 (marginal, 0.08 h)	89.7° 11:05	6.06	56%	114.1°
2033-05-07 Sat	2	—	unknown	04:55–05:00 (marginal, 0.08 h)	89.8° 11:00	6.0	66%	123.3°
2033-05-08 Sun	2	—	unknown	04:50–05:00 (marginal, 0.17 h)	89.7° 10:55	5.95	74%	131.7°
2033-05-09 Mon	2	—	unknown	04:50–05:00 (marginal, 0.17 h)	89.6° 10:50	5.89	82%	138.9°
2033-05-10 Tue	3	—	unknown	04:45–05:00 (marginal, 0.25 h)	89.5° 10:50	5.83	89%	144.0°
2033-05-11 Wed	3	—	unknown	04:05–04:15 (marginal, 0.17 h)	89.7° 10:45	5.78	94%	146.2°
2033-05-12 Thu	3	—	unknown	04:45–04:55 (marginal, 0.17 h)	89.8° 10:40	5.72	98%	144.6°
2033-05-13 Fri	3	—	unknown	04:00–04:10 (marginal, 0.17 h)	89.7° 10:35	5.67	100%	139.8°
2033-05-14 Sat	4	—	unknown	03:55–04:10 (marginal, 0.25 h)	89.5° 10:30	5.62	100%	132.4°
2033-05-15 Sun	4	—	unknown	03:50–04:05 (marginal, 0.25 h)	89.6° 10:30	5.56	98%	123.5°
2033-05-16 Mon	4	—	unknown	03:45–04:05 (marginal, 0.33 h)	89.7° 10:25	5.51	94%	113.6°
2033-05-17 Tue	4	—	unknown	03:45–04:05 (marginal, 0.33 h)	89.7° 10:20	5.46	87%	103.0°
2033-05-18 Wed	4	—	unknown	03:40–04:00 (marginal, 0.33 h)	89.6° 10:15	5.41	80%	92.0°
2033-05-19 Thu	4	—	unknown	03:35–04:00 (marginal, 0.42 h)	89.5° 10:15	5.35	70%	80.9°
2033-05-20 Fri	5	—	unknown	03:30–04:00 (marginal, 0.5 h)	89.6° 10:10	5.3	60%	69.7°
2033-05-21 Sat	6	—	unknown	03:30–04:00 (marginal, 0.5 h)	89.8° 10:05	5.26	48%	58.7°
2033-05-22 Sun	7	—	unknown	03:25–03:55 (marginal, 0.5 h)	89.7° 10:00	5.21	37%	48.6°
2033-05-23 Mon	8	—	unknown	03:20–03:55 (marginal, 0.58 h)	89.6° 09:55	5.16	26%	40.1°
2033-05-24 Tue	11	—	unknown	03:50–03:55 (good, 0.08 h)	89.5° 09:55	5.11	16%	34.7°
2033-05-25 Wed	12	—	unknown	03:45–03:55 (good, 0.17 h)	89.7° 09:50	5.07	9%	34.4°
2033-05-26 Thu	12	—	unknown	03:40–03:50 (good, 0.17 h)	89.8° 09:45	5.02	3%	39.1°
2033-05-27 Fri	14	—	unknown	03:35–03:50 (good, 0.25 h)	89.7° 09:40	4.98	0%	47.3°
2033-05-28 Sat	15	—	unknown	03:35–03:50 (good, 0.25 h)	89.5° 09:35	4.94	0%	57.3°
2033-05-29 Sun	16	—	unknown	03:30–03:50 (good, 0.33 h)	89.6° 09:35	4.9	3%	68.1°
2033-05-30 Mon	17	—	unknown	03:25–03:45 (good, 0.33 h)	89.7° 09:30	4.86	8%	79.1°
2033-05-31 Tue	18	—	unknown	03:20–03:45 (good, 0.42 h)	89.7° 09:25	4.82	14%	90.0°
2033-06-01 Wed	19	—	unknown	03:20–03:45 (good, 0.42 h)	89.6° 09:20	4.79	22%	100.6°
2033-06-02 Thu	21	—	unknown	03:15–03:45 (good, 0.5 h)	89.5° 09:20	4.75	31%	110.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-05-04&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.