Date ranges in CAML queries

Question

I have a list with a DateTime field.

I want to select the items within a range.

I use this code

<Where>  
 <And>
  <Geq>
    <FieldRef Name='SendDate' /> <Value IncludeTimeValue='TRUE' Type='DateTime'>8/3/2012 12:00:00 AM</Value>
  </Geq>
  <Leq>
    <FieldRef Name='SendDate' />
    <Value IncludeTimeValue='TRUE' Type='DateTime'>8/5/2012 12:00:00 AM</Value> 
  </Leq>
 </And>
</Where>

The list actually has items within this range but it doesn't return any of them.

Answer 1

What is important here is to get the datetime format right. If you use it programatically you could either use this

string sendDate = sendDate.ToString("yyyy-MM-ddTHH:mm:ssZ");

..or you could use the SPUtility.CreateISO8601DateTimeFromSystemDateTime method to achieve the same. Beyond this you could also consider using "relative" expressions based on Today such in (translated into "30 days ago")

 <Geq>
        <FieldRef Name="SendDate" />
<Value Type='DateTime'>
               <Today OffsetDays='-30' />
            </Value>
      </Geq>

Answer 2

Create your query with the U2U Caml Query builder:

http://www.u2u.be/Tools/wincamlquerybuilder/CamlQueryBuilder.aspx

(This works with 2010 as well)

Ideally the following query should work:

<Query>
  <Where>
    <And>
      <Geq>
        <FieldRef Name="SendDate" />
          <Value IncludeTimeValue="TRUE" Type="DateTime">2011-01-01T15:55:52Z</Value>
      </Geq>
      <Leq>
        <FieldRef Name="SendDate" />
        <Value IncludeTimeValue="TRUE" Type="DateTime">2011-12-31T15:56:29Z</Value>
      </Leq>
    </And>
  </Where>
</Query>