Log in to your Blogger account. Go to "Design" --> "Edit HTML". (if you are using Blogger new interface go to "Template" --> "Edit HTML").
Click on "Expand Widget Templates".
Find this:
Added Jan 6, 2010
Replace it with this:
Added <data:post.timestamp/>
Save your template and you are done.
Note : I have fixed this issue in "Aparatus" templates. If you are going to use these templates first time, can download them without applying this solution:
http://www.premiumbloggertemplates.com/2010/11/aparatus-premium-blogger-template.html
http://www.premiumbloggertemplates.com/2010/11/aparatus-black-premium-blogger-template.html
http://www.premiumbloggertemplates.com/2010/11/aparatus-blue-premium-blogger-template.html
http://www.premiumbloggertemplates.com/2010/11/aparatus-green-premium-blogger-template.html