Yes, you can update the times and dates for an auction at any time via the 'Auction Details' page, by clicking  [Auction Set-Up]. 

Click on [Save] to apply any changes.

Note : If you change the 'Prespecified First Lot Close Time' for an auction after lots have been allocated the close times for all lots in the auction will automatically update, however you will need to reschedule the lots so that the end times are updated in the admin view. See Schedule Lots.

Note :  You must not change the auction times once lots in an auction have started to close.