This is funny, last backup was done in the future 05/01/2013 (tomorrow), as today is 04/30/2013.
Timezone is correctly configured as Europe/Madrid in the appliance as well as in vCenter and my PC.
Dates are displayed correct elsewhere: If i login the appliance it shows correct time. Web client displays date correct.
It looks like a display issue. If I sort by date it mistakes date around 2AM:
Notice wrong sort order and there are backups that happened in the future.