How to Eliminate Post Date

the date of posting blogger, I want to do? The first entry Edit HTML page and search-header h2.date (if already met add visibility: hidden; of the code. see example code below:

h2.date-header (
margin: .3 em 0 0;
padding: 0;
font-size: 80%;
color: # 777;
height: 0px;
visibility: hidden;
)

During the attempt