Trying to import csv file

The file structure is

Date              
 2/11/2012      0.00165
 2/15/2012      0.01215
 2/16/2012      0.00126

But the program gives

"label strings can't be consistent dates
treating these as undated data"

Choosing restructure the file with time series would alter the existing date

Another question is what is the command to layer many series on gnuplots ignoring the scaling or display other series scale on right or left axis