PSCSV

https://github.com/SFXD/PSCSV 
 A powershell script to help Salesforce admins and consultant to save time and do data load operations without having to rely on Excel. 
 Current list of stuff the script can do: 
 
 transcode a file from one encoding or separator to another 
 remap values in a column from one to another - reformat Dates from whatever format to the salesforce format 
 reformat Date Times from whatever format to the salesforce format 
 replace whatever you want in a column with "" 
 great if someone is sending you files with null .