This is the code I have for one of my columns a vf page that is being submitted from a site.
<apex:pageblock title="">
<apex:pageBlockSection title="Details">
<apex:pageBlockSectionItem labelStyle="100%" dataStyle="100%">
<label for="risk identification / impact analysis">Risk Identification / Impact Analysis <b><font size="3" color ="FF0000">*</font></b> </label><br/>
<textarea id="00N0g000003cTCBEA2" maxlength="255" name="00N0g000003cTCBEA2" style="width:100%;height:70px;" wrap="soft" required="true" placeholder="Describe the Risks and Impact of the suggested change to work that is already complete."/><br/><br/>
<label for="implementation steps">Implementation Steps <b><font size="3" color ="FF0000">*</font></b> </label><br/>
<textarea id="00N0g000003cTC9EAM" maxlength="32000" name="00N0g000003cTC9EAM" style="width:100%;height:70px;" wrap="soft" required="true" placeholder="Based on the impact, state the estimated date for implementing the requested change. State the new estimated project completion date."/><br/><br/>
<label for="test plan">Test Plan <b><font size="3" color ="FF0000">*</font></b> </label><br/>
<textarea id="00N0g000003cTCDEA2" maxlength="255" name="00N0g000003cTCDEA2" style="width:100%;height:70px;" wrap="soft" required="true" placeholder="Describe the Test Plan."/><br/><br/>
<label for="rollback plan">Rollback Plan <b><font size="3" color ="FF0000">*</font></b> </label><br/>
<textarea id="00N0g000003cTCCEA2" maxlength="255" name="00N0g000003cTCCEA2" style="width:100%;height:70px;" wrap="soft" required="true" placeholder="Describe the Rollback Plan."/><br/><br/>
<label for="impacted business units">Impacted Business Units <b><font size="3" color ="FF0000">*</font></b> </label><br/>
<textarea id="00N0g000003cImAEAU" maxlength="255" name="00N0g000003cImAEAU" style="width:100%;height:70px;" wrap="soft" required="true" placeholder="Business units impacted by the release."/><br/><br/> <label for ="Release Date"> Release Date <b><font size="3" color = "FF0000">*</font></b></label><br/>
<span class="dateInput dateOnlyInput"><input id="00N0g000003c8NC" name="00N0g000003c8NC" style="width:30%;height:25px;" type="date" /></span><br/> <br/><br/>
<input type="submit" name="submit" style="width:31%;height:28px;" /><br/><br/>
</apex:pageBlockSectionItem>
</apex:pageBlockSection>
</apex:pageBlock>

All fields are pulling onto the case except the Release date field. But when I change the code (bolded and underlined above) to read type="text" it submits fine. I changed it to type="date" to allow the datepicker to show in the page so you wouldn't have to type the date in manually. 
<label for ="Release Date"> Release Date <b><font size="3" color = "FF0000">*</font></b></label><br/>
<span class="dateInput dateOnlyInput"><input id="00N0g000003c8NC" name="00N0g000003c8NC" style="width:30%;height:25px;" type="text" /></span><br/> <br/><br/>
<input type="submit" name="submit" style="width:31%;height:28px;" />

Any ideas on how to get this to work correctly to that when you click into the release date field on the form it opens a calendar to pick the date from?