When the browser window is not reopened or reloaded at the beginning of the day the old times from a previous day are still shown. The old times are stored if a project is activated or something is changed. The webtimex should check if the day has changed when displaying the times and create a new day record if it is a new day.
Workaround
As a workaround, refresh the browser page when starting a new day, or close the page at the end of the day and open it the next day.