Drag year end across the note's term and watch the interest split between two years.
$50
15 days
$250
75 days
A earns interest every day it is outstanding, whether or not the fiscal year ends before it matures. If year end falls inside the note's term, the days so far belong on this year's income statement.
The adjusting entry accrues only what has been earned to date. The rest waits, unrecorded, until the note is actually paid — the same accrual logic as any other adjusting entry.