A recent article published by Mashable highlights a study showing how into work US and British office works are getting freely giving time beyond the normal due to increases in technologies, and for it business are being more lax with the work schedule. The study showed workers were checking work related emails and preforming research into maters or colaborating with co-workers before they even clock in, but business are now feeling comfortable letting them clock in shy of forty minutes late in the States, and close to thirty abroad.
But the mixing does not end there. Workers are taking work home and checking emails and processing work related projects till approximately after 7pm. Two hours after they have left work. So that is approximately three hours of free work that employers are getting out of employees for free every day just for not being jerks. But to put the cherry on top these employees are working on their lunch breaks to.
So the lesson he is let your employees that work for the love of the job, recognition and have that general slack open view to life be late to work. You do not have to pay them for the time they are not on the clock and they will be more productive.