I've used FileMaker to track time on consulting projects for years.
I created a related table of "time slices". It had two TimeStamp fields--since I've been known to start before midnight and stop after midnight I used TimeStamp fields instead of time, named In and Out. Creating a new "time slice" record auto-entered the creation TimeStamp into In. Entering the Out field tripped the OnObjectEnter trigger and performed a script with this script:
If [ IsEmpty (TimeSlices::Out ) ]
Set Field [ TimeSlices::Out ; Get ( CurrentTimeStamp ) ]
Out - In then computes the elapsed time in seconds.
I can create as many records in timeSlices each day as I need to log my time on a given project. To "Pause" the time record, I just click the Out field and start a new record when I return to work on the project.