It is possible to log more than a day on a particular date
and have timesheet app automatically split the work across the
reported day and previous days.
For example, if you log 3d on a single task with a start date of Mar
19, timesheet will have 1d for Mar 19, 1d for Mar 18, and 1d
for Mar 17.
Note, it works only if you Log Work with the app dialog, instead of JIRA native dialog, or if you switch Time Tracking provider to “Timesheet Reports and Gadgets provided time tracking” or to “Time Reports provided time tracking” in Jira Settings - Issues configuration, please see https://confluence.atlassian.com/adminjiracloud/configuring-time-tracking-818578858.html#Configuringtimetracking-Changethetimetrackingprovider also.