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 North America Nebula: 02-25 (20), 02-24 (18), 02-20 (17), 02-21 (17), 02-22 (17) — by astronomy; check the weather when the night is within four days.

2030-01-27astronomy score per night — click a bar for that night2030-02-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-01-27 Sun	13	—	unknown	19:10–19:15 (good, 0.08 h)	87.2° 12:55	10.91	37%	100.8°
2030-01-28 Mon	12	—	unknown	18:35–19:45 (marginal, 1.17 h)	87.2° 12:50	10.88	26%	92.2°
2030-01-29 Tue	11	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.2° 12:45	10.85	17%	83.6°
2030-01-30 Wed	10	—	unknown	19:10–19:35 (marginal, 0.42 h)	87.2° 12:40	10.82	9%	75.3°
2030-01-31 Thu	9	—	unknown	19:15–19:35 (marginal, 0.33 h)	87.2° 12:40	10.79	4%	67.6°
2030-02-01 Fri	9	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:35	10.76	1%	61.1°
2030-02-02 Sat	9	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.2° 12:30	10.72	0%	56.1°
2030-02-03 Sun	9	—	unknown	05:30–06:00 (marginal, 0.5 h)	87.2° 12:25	10.69	2%	53.2°
2030-02-04 Mon	8	—	unknown	05:30–05:55 (marginal, 0.42 h)	87.2° 12:20	10.65	6%	52.6°
2030-02-05 Tue	9	—	unknown	05:25–05:55 (marginal, 0.5 h)	87.2° 12:20	10.62	12%	54.1°
2030-02-06 Wed	10	—	unknown	05:20–06:25 (marginal, 1.08 h)	87.2° 12:15	10.58	19%	57.5°
2030-02-07 Thu	10	—	unknown	05:50–05:55 (good, 0.08 h)	87.2° 12:10	10.55	27%	62.3°
2030-02-08 Fri	11	—	unknown	05:50–05:55 (good, 0.08 h)	87.2° 12:05	10.51	36%	68.1°
2030-02-09 Sat	11	—	unknown	05:45–05:50 (good, 0.08 h)	87.2° 12:00	10.48	45%	74.5°
2030-02-10 Sun	12	—	unknown	05:40–05:50 (good, 0.17 h)	87.2° 11:55	10.44	54%	81.4°
2030-02-11 Mon	12	—	unknown	05:35–05:50 (good, 0.25 h)	87.2° 11:50	10.4	64%	88.6°
2030-02-12 Tue	14	—	unknown	05:30–05:50 (good, 0.33 h)	87.2° 11:45	10.36	72%	95.9°
2030-02-13 Wed	13	—	unknown	05:30–05:45 (good, 0.25 h)	87.2° 11:45	10.32	81%	103.2°
2030-02-14 Thu	14	—	unknown	05:25–05:45 (good, 0.33 h)	87.2° 11:40	10.28	88%	110.2°
2030-02-15 Fri	13	—	unknown	05:30–05:45 (good, 0.25 h)	87.2° 11:35	10.24	94%	116.6°
2030-02-16 Sat	14	—	unknown	05:25–05:45 (good, 0.33 h)	87.2° 11:30	10.2	98%	122.0°
2030-02-17 Sun	14	—	unknown	05:25–05:40 (good, 0.25 h)	87.2° 11:25	10.16	100%	125.8°
2030-02-18 Mon	15	—	unknown	05:20–05:40 (good, 0.33 h)	87.2° 11:25	10.12	99%	127.4°
2030-02-19 Tue	16	—	unknown	05:15–05:40 (good, 0.42 h)	87.2° 11:20	10.08	96%	126.4°
2030-02-20 Wed	17	—	unknown	05:15–05:40 (good, 0.42 h)	87.2° 11:15	10.04	91%	123.0°
2030-02-21 Thu	17	—	unknown	05:10–05:35 (good, 0.42 h)	87.2° 11:10	10.0	83%	117.4°
2030-02-22 Fri	17	—	unknown	05:05–05:35 (good, 0.5 h)	87.2° 11:10	9.95	74%	110.4°
2030-02-23 Sat	17	—	unknown	05:05–05:35 (good, 0.5 h)	87.2° 11:05	9.91	63%	102.4°
2030-02-24 Sun	18	—	unknown	05:00–05:30 (good, 0.5 h)	87.2° 11:00	9.87	52%	94.0°
2030-02-25 Mon	20	—	unknown	04:55–05:30 (good, 0.58 h)	87.2° 10:55	9.82	40%	85.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-01-27&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.