Are you looking for something like this??
(Date range is from Week 37 -2012 to week 25 2013)
Create a sheet with week number and date
Start Week Date
End Week Date
Note down the starting of the week date that you want to have on your axis.
Go to the chart:
Right click ->Format and change it to highlighted one:
Right click -> edit axis
Give the date range
Start : One day before week starting day i.e (09-09-2012) - 1 day = 08-09-2012
End Date = Last date of the week that you want to display:
Could you mark my answer as correct.