How to hide blog date header :

Follow steps-

step 1 :Dashboard

step 2 :Design

step 3 :Edit html

step 4 :go to h2.date-header { in template code

step 5 :add new line : visibility:hidden; after h2.date-header { .

h2.date-header {
visibility:hidden;
margin:1.5em 0 .5em;
}

step 6 :click on save.