Q:

Javascript CAML Query using DateTime

I have the following CAML:
<Where>
    <And>
        <Eq>
            <FieldRef Name='Author' LookupId='TRUE' />
            <Value Type='User'>473</Value>
        </Eq>
        <Eq>
            <FieldRef Name='Datum' />
            <Value Type='DateTime'>2015-06-05T00:00:00Z</Value>
        </Eq>
    </And>
</Where>

In my list I have 8 items, 7 of these have Author equals 473 and 2 of these have Datum equals 2015-06-05.  Whatever value I pass to the Datum i always get 7 items. 
What is wrong? 

A:

I wasn't able to find out the problem, but with the following workaround I got it:
<Where>
<And>
    <Eq>
        <FieldRef Name='Author' LookupId='TRUE' />
        <Value Type='User'>473</Value>
    </Eq>
    <And>
        <Leq>
            <FieldRef Name='Datum' />
            <Value Type='DateTime'>2015-06-05 00:00:00</Value>
        </Leq>
        <Geq>
            <FieldRef Name='Datum' />
            <Value Type='DateTime'>2015-06-05 00:00:00</Value>
        </Geq>
    </And>
</And>

