When trying to Log Work the date started was correctly entered but the time was wrong (because it was showing the current time). I manually changed the numbers to 15:53 and when submitting the form was presented with the error "You must specify a date on which the work occurred.". It took me a little while to realise that the issue was my use of 24hr format when the field only accepts 12hr.
It would be nice if either the error handling was a bit more intelligent or the field itself was.